Lafayette Instrument Company is a household name among examiners, and this full product guide surveys the equipment that powers so many a lie detector test.
The definitive buyer's comparison of every Lafayette polygraph system for professional examiners. From the flagship LX5000 to the next-generation LX7, this guide consolidates everything you need to make an informed purchasing decision, including the ParagonX line now unified under the Lafayette umbrella following the 2022 Limestone Technologies acquisition.
TL;DR — The Short Version
- LX5000 — Lafayette's flagship 9-channel system, preferred by federal agencies, with 24-bit A/D conversion and wireless Bluetooth capability.
- LX6 — A 10-channel professional system with 32-bit A/D conversion and quick-release connectors, ideal for private practice and law enforcement.
- LX7 — Lafayette's next-generation system featuring improved PPG sensors, Pulse Arrival Time (PAT) measurement, and enhanced cable management.
- ParagonX — Now part of the Lafayette family following the 2022 acquisition of Limestone Technologies; operates on its own Polygraph Professional Suite software.
- OSS-3 — An algorithmic scoring module developed by Raymond Nelson, Mark Handler, and Donald Krapohl, achieving 85–92% accuracy under laboratory conditions.
- LXSoftware and LXEdge — Lafayette's two software platforms covering legacy (LX4000/LX5000) and current-generation (LX6/LX7/Paragon) hardware respectively.
- Best for new examiners — The LX6 offers excellent value with lease financing available; the LX5000 remains the choice for federal and high-stakes environments.
Who This Guide Is For
- Polygraph examiners evaluating their first professional system purchase
- Agency procurement officers comparing polygraph instrumentation options
- Experienced examiners considering an upgrade from older Lafayette models
- PCSOT examiners needing systems that meet post-conviction testing standards
- Polygraph school students researching equipment before graduation
- Private practice owners calculating return on investment for new equipment
- Anyone comparing Lafayette products against competing manufacturers
Lafayette Instrument Company: History and Industry Position
From a Small Shed to Global Market Leader
Lafayette Instrument Company was founded in 1947 by Max Wastl, a German immigrant who studied Electrical Engineering at Purdue University [1]Verified Our Story — Lafayette Instrument Company
Confirms Lafayette was founded in 1947 by Max Wastl, first polygraph in 1972, LX6 and LX7 specifications, company timeline. He established the company with a single employee and an 8-by-10-foot shed in Lafayette, Indiana [1]Verified Our Story — Lafayette Instrument Company
Confirms Lafayette was founded in 1947 by Max Wastl, first polygraph in 1972, LX6 and LX7 specifications, company timeline. The first catalog was printed in 1954, and under Wastl's leadership, the company quickly became the market leader in psychophysiological instrumentation for schools and university laboratories [1]Verified Our Story — Lafayette Instrument Company
Confirms Lafayette was founded in 1947 by Max Wastl, first polygraph in 1972, LX6 and LX7 specifications, company timeline.
In 1972, Lafayette produced its first polygraph instrument, leveraging its expertise in physiological testing [1]Verified Our Story — Lafayette Instrument Company
Confirms Lafayette was founded in 1947 by Max Wastl, first polygraph in 1972, LX6 and LX7 specifications, company timeline. Since then, Lafayette has grown into the world's leading manufacturer of polygraph instrumentation, distributing credibility assessment instruments to private examiners, government, and military organizations around the world [1]Verified Our Story — Lafayette Instrument Company
Confirms Lafayette was founded in 1947 by Max Wastl, first polygraph in 1972, LX6 and LX7 specifications, company timeline. The company has achieved a global polygraph market share of approximately 90 percent [2]Verified History of Polygraph — ARGO-A
Confirms Lafayette's approximately 90% global polygraph market share and the LX5000-SW wireless system introduction in 2007.
Lafayette expanded significantly through strategic acquisitions. The company acquired Campden Instruments in the United Kingdom in 1998, founded the PEAK Credibility Assessment Training Center in 2016, acquired Limestone Technologies in August 2022, and added Aurora Scientific and Actimetrics in 2023 [1]Verified Our Story — Lafayette Instrument Company
Confirms Lafayette was founded in 1947 by Max Wastl, first polygraph in 1972, LX6 and LX7 specifications, company timeline[3]Verified Lafayette Instrument Co. Acquires Limestone Technologies — PR Newswire
Confirms Lafayette acquired Limestone Technologies on August 12, 2022 via Branford Castle Partners. In March 2024, Lafayette received ISO 9001:2015 accreditation for its quality management system [4]Verified ISO 9001:2015 Certification — Lafayette Instrument
Confirms Lafayette received ISO 9001:2015 accreditation on March 7, 2024, and was named one of Indiana's Best Places to Work by the Indiana Chamber of Commerce [4]Verified ISO 9001:2015 Certification — Lafayette Instrument
Confirms Lafayette received ISO 9001:2015 accreditation on March 7, 2024.
The company's headquarters remain at 3700 Sagamore Parkway North, Lafayette, Indiana 47904, where manufacturing, research and development, and customer support operations are centralized [1]Verified Our Story — Lafayette Instrument Company
Confirms Lafayette was founded in 1947 by Max Wastl, first polygraph in 1972, LX6 and LX7 specifications, company timeline. This American manufacturing base is significant for government purchasers with domestic sourcing requirements. For more on the evolution of lie detection technology, see our article on the history of polygraph from the 1920s.
The Unified Lafayette Ecosystem
What distinguishes Lafayette from other manufacturers is the breadth of their product ecosystem. Rather than selling a single polygraph unit, Lafayette offers a complete infrastructure: hardware systems at multiple price points (LX5000, LX6, LX7, ParagonX), two unified software platforms (LXSoftware and LXEdge), proprietary sensors and transducers, algorithmic scoring tools including the OSS-3 and ESS-M, training resources through the PEAK Credibility Assessment Training Center, and ongoing technical support [1]Verified Our Story — Lafayette Instrument Company
Confirms Lafayette was founded in 1947 by Max Wastl, first polygraph in 1972, LX6 and LX7 specifications, company timeline[5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features.
Lafayette is positioned at the forefront of credibility assessment with a global family of leading brands including Campden Instruments, Aurora Scientific, Actimetrics, and Limestone Technologies [4]Verified ISO 9001:2015 Certification — Lafayette Instrument
Confirms Lafayette received ISO 9001:2015 accreditation on March 7, 2024. The company's influence extends well beyond hardware manufacturing — researcher Raymond Nelson, a research specialist with Lafayette and past-President of the American Polygraph Association, has been instrumental in developing the OSS-3 scoring algorithm and the Empirical Scoring System [6]Verified Brute-Force Comparison: A Monte Carlo Study of OSS-3 and Human Polygraph Scorers
Confirms OSS-3 was developed by Nelson, Krapohl, and Handler; demonstrates balanced sensitivity/specificity and perfect reliability[7]Verified Using the Empirical Scoring System
Describes ESS procedures and validation data across 5,192 scored results of 732 confirmed examinations. Understanding the role of the polygraph examiner is critical context for appreciating how these systems integrate into professional practice.
The LX5000: Lafayette's Flagship Polygraph System
Core Physiological Channels and Specifications
The LX5000 represents the pinnacle of Lafayette's polygraph product line and is the system most commonly associated with federal-level testing in the United States. It records a total of nine channels simultaneously [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components and features 24-bit analog-to-digital conversion with a data transfer rate of up to 360 samples per second across all channels [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components.
The LX5000 records the standard polygraph channels required by the American Polygraph Association for a valid examination:
Pneumograph (Respiration): Two pneumatic sensors measure thoracic and abdominal breathing patterns independently, capturing changes in respiration rate, depth, and rhythm.
Electrodermal Activity (EDA): Measures the electrical conductivity of the skin via finger electrodes, with a selectable GSR or GSC channel. Research confirms that the electrodermal response provides the greatest contribution to diagnostic accuracy in comparison question tests [9]Verified An EDA Primer for Polygraph Examiners
Confirms electrodermal response provides the greatest contribution to diagnostic accuracy in comparison question tests.
Cardiovascular: A blood pressure cuff records cardiovascular activity including relative blood pressure changes, heart rate, and pulse amplitude.
Plethysmograph (PPG): A dedicated photoelectric plethysmograph channel measures peripheral vasomotor activity. The historical roots of plethysmographic measurement trace back to Angelo Mosso's pioneering experiments in the 1870s, where he used the plethysmograph to study blood pressure changes in response to stimuli [10]Verified The European Roots of Instrumental Lie Detection
Confirms European researchers including Mosso, Lombroso, and Benussi developed fundamental physiological measurement instruments[11]Verified First Attempts at Practical Use of Instrumental Lie Detection
Confirms instrumental lie detection moved from first operational use in 1917 to routine deployment in 15 federal agencies by the post-WWII era. Cesare Lombroso later adapted similar instruments — specifically the hydrosphygmograph — for deception detection in criminal suspects in 1895 [10]Verified The European Roots of Instrumental Lie Detection
Confirms European researchers including Mosso, Lombroso, and Benussi developed fundamental physiological measurement instruments[11]Verified First Attempts at Practical Use of Instrumental Lie Detection
Confirms instrumental lie detection moved from first operational use in 1917 to routine deployment in 15 federal agencies by the post-WWII era.
Activity Sensor: A seat-based movement sensor detects deliberate or involuntary physical movements, which is important for identifying countermeasure attempts and movement artifacts. Additional arm and foot activity sensors are available [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components.
Hardware Design and Connectivity
The LX5000 uses a compact data acquisition system measuring just 7 3/8 inches wide by 2 3/4 inches deep by 1 3/8 inches high, weighing only 0.52 lbs [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components. The system connects to a Windows-based computer via USB cable or wirelessly via Bluetooth [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components. This wireless capability, introduced in 2007 when Lafayette created the first wireless computerized polygraph (LX5000-SW), gives examiners significant flexibility in field deployments [2]Verified History of Polygraph — ARGO-A
Confirms Lafayette's approximately 90% global polygraph market share and the LX5000-SW wireless system introduction in 2007.
The LX5000 is designed to work exclusively with LXSoftware, Lafayette's proprietary polygraph data collection and analysis platform, which is bundled with the Objective Scoring System (OSS-3) scoring algorithm and APL's PolyScore [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components[5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features. This tight integration means that hardware calibration, channel configuration, data recording, chart review, algorithmic scoring, and report generation all occur within a single software environment. The system includes a 3-year warranty and lifetime technical support [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components. To understand how these instruments meet professional standards, see our guide on APA standards for polygraph instrument calibration and maintenance.
Who Uses the LX5000
The LX5000 is the system of choice for many federal agencies, including components of the Department of Defense and various intelligence community organizations [1]Verified Our Story — Lafayette Instrument Company
Confirms Lafayette was founded in 1947 by Max Wastl, first polygraph in 1972, LX6 and LX7 specifications, company timeline. Lafayette's instruments have been preferred by polygraph examiners in approximately 90 countries using polygraphs [2]Verified History of Polygraph — ARGO-A
Confirms Lafayette's approximately 90% global polygraph market share and the LX5000-SW wireless system introduction in 2007. The Department of Defense's standardization of federal polygraph testing created institutional procurement patterns that favor established, thoroughly validated systems, and the LX5000 has benefited from this dynamic. It is also widely used by state and local law enforcement agencies conducting criminal investigation polygraphs and pre-employment screening.
The LX6: 10-Channel Professional Workhorse
Technical Specifications and Advantages
The LX6 is Lafayette's 10-channel polygraph system, designed as a more rugged platform with significant hardware upgrades over the LX5000 [12]Verified LX6 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX6 as 10-channel system with quick-release connectors, lease financing details, and LXEdge compatibility. Key specifications include new quick-release input connectors rated for twice the mating cycles of connectors used by other manufacturers, a data transfer rate of up to 360 samples per second across all channels, and 32-bit analog-to-digital conversion (compared to the LX5000's 24-bit) [12]Verified LX6 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX6 as 10-channel system with quick-release connectors, lease financing details, and LXEdge compatibility[13]Verified LX6 Specifications — Lafayette Instrument Our Story
Confirms LX6 has 32-bit A/D conversion, 360 samples/sec, 10 channels, and quick-release connectors.
The LX6 features a selectable GSR or GSC channel, a dedicated seat sensor, a PLE (plethysmograph) channel, and 3 additional auxiliary channels [12]Verified LX6 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX6 as 10-channel system with quick-release connectors, lease financing details, and LXEdge compatibility. Electronic sensors cannot be incorrectly connected thanks to the system's keyed connector design [13]Verified LX6 Specifications — Lafayette Instrument Our Story
Confirms LX6 has 32-bit A/D conversion, 360 samples/sec, 10 channels, and quick-release connectors. The system is compatible with both LXSoftware and Lafayette's next-generation LXEdge software platform [12]Verified LX6 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX6 as 10-channel system with quick-release connectors, lease financing details, and LXEdge compatibility.
Lease Financing and Value Proposition
Lafayette offers lease financing for the LX6, making it accessible to individual purchasers and smaller agencies. Monthly payments can typically be covered after a few examinations, with full ownership after 36 months [13]Verified LX6 Specifications — Lafayette Instrument Our Story
Confirms LX6 has 32-bit A/D conversion, 360 samples/sec, 10 channels, and quick-release connectors. The lease includes a full DAS warranty for the life of the lease and a one-year warranty on system accessories [13]Verified LX6 Specifications — Lafayette Instrument Our Story
Confirms LX6 has 32-bit A/D conversion, 360 samples/sec, 10 channels, and quick-release connectors.
The LX6 is well-suited for examiners conducting private lie detector tests in civil matters, relationship testing, PCSOT maintenance examinations, and routine law enforcement polygraphs. Examiners who run mobile practices — traveling to attorney offices, probation departments, or private residences — appreciate the LX6's portability and straightforward setup. For those exploring a career in polygraph examination, understanding the ideal conditions for testing and the uses and benefits of lie detector tests provides essential context.
The LX7: Lafayette's Next-Generation System
New Features and Innovations
The LX7 is Lafayette's newest polygraph system, designed to elevate accuracy, consistency, and usability in the field [14]Verified LX7 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design. It represents a significant step forward in polygraph instrumentation with several innovative features.
The LX7 features improved detection of subtle, rapid changes in pulse blood volume via the photoelectric plethysmograph (PPG) sensor, delivering more reliable cardiovascular readings across a broader selection of examinees [14]Verified LX7 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design. A major innovation is the Pulse Arrival Time (PAT) measurement, which calculates the time between the ECG pulse and PPG waveform, providing a measurement that is directly correlated to blood pressure [14]Verified LX7 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design. Research has found that PAT is as effective as the cardiograph for discriminating between truthful and deceptive people in a polygraph test, and the LX7 supports research toward PAT as an eventual replacement for the traditional cardio measurement [14]Verified LX7 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design.
The LX7 maintains high-quality reliable connectors compatible with LX6 accessories while employing a curved design that improves cable management for a cleaner workspace [14]Verified LX7 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design. The system is compatible with both LXSoftware and LXEdge, and upgrade paths are available from older systems [14]Verified LX7 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design.
Compatibility and Upgrade Pathways
The LX7 shares sensor compatibility with the LX6, meaning pneumo assemblies, blood pressure cuffs, EDA assemblies, pump bulb assemblies, and activity sensors are interchangeable between both systems [14]Verified LX7 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design. LXEdge is compatible with the Lafayette LX6 and LX7 along with the Limestone Paragon series [15]Verified LXEdge — Polygraph by Lafayette Instrument Company
Confirms LXEdge is compatible with LX6, LX7, and Limestone Paragon series, providing a unified software platform across Lafayette's current-generation hardware.
Examiners using older LX5000 or LX4000 systems can upgrade to the LX7 through Lafayette's upgrade programs, receiving the complete LX7 system package [14]Verified LX7 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design. For a comparison with systems from other manufacturers, see our Axciton vs. Stoelting polygraph systems comparison and our Stoelting portable polygraph armrest review.
The ParagonX: Now Part of the Lafayette Family
The 2022 Limestone Technologies Acquisition
A critical update since earlier guides: the ParagonX is now part of the Lafayette product family. In August 2022, Lafayette Instrument acquired Limestone Technologies, originally headquartered in Kingston, Ontario, Canada [3]Verified Lafayette Instrument Co. Acquires Limestone Technologies — PR Newswire
Confirms Lafayette acquired Limestone Technologies on August 12, 2022 via Branford Castle Partners[16]Verified Limestone Technologies Inc. — LinkedIn
Confirms Limestone Technologies corporate office is located in Kingston, Ontario, Canada. The acquisition was facilitated by Branford Castle Partners, a New York-based private equity firm that owns Lafayette Instrument [3]Verified Lafayette Instrument Co. Acquires Limestone Technologies — PR Newswire
Confirms Lafayette acquired Limestone Technologies on August 12, 2022 via Branford Castle Partners.
Limestone Technologies had been a leading Canada-based manufacturer of polygraph equipment with an established position in various international markets [3]Verified Lafayette Instrument Co. Acquires Limestone Technologies — PR Newswire
Confirms Lafayette acquired Limestone Technologies on August 12, 2022 via Branford Castle Partners. The acquisition expanded Lafayette's credibility assessment staff, product line, and market reach [3]Verified Lafayette Instrument Co. Acquires Limestone Technologies — PR Newswire
Confirms Lafayette acquired Limestone Technologies on August 12, 2022 via Branford Castle Partners. Limestone Technologies now operates as a subsidiary of Lafayette Instrument Company [17]Verified Limestone Technologies — Limestone Polygraph by Lafayette Instrument Company
Confirms Limestone Technologies is a subsidiary of Lafayette Instrument Company since August 2022.
Jennifer Rider, President of Lafayette Instrument Company, stated that the acquisition brought together two companies with decades of experience serving the credibility assessment community [3]Verified Lafayette Instrument Co. Acquires Limestone Technologies — PR Newswire
Confirms Lafayette acquired Limestone Technologies on August 12, 2022 via Branford Castle Partners. For a detailed technical overview, see our Limestone Technologies ParagonX Pro Suite review.
ParagonX System and Polygraph Professional Suite
The ParagonX delivers on performance, reliability, and innovation as a modular professional-grade polygraph system [17]Verified Limestone Technologies — Limestone Polygraph by Lafayette Instrument Company
Confirms Limestone Technologies is a subsidiary of Lafayette Instrument Company since August 2022. It operates on its own Polygraph Professional Suite software, which is separate from LXSoftware but is now also supported by Lafayette's LXEdge platform [15]Verified LXEdge — Polygraph by Lafayette Instrument Company
Confirms LXEdge is compatible with LX6, LX7, and Limestone Paragon series. Limestone Technologies was notable for being the first polygraph vendor with an open data format, allowing data export to Excel, Word, SAS, and other tools [18]Verified Limestone Technologies Products — Axxonet
Confirms Polygraph Professional Suite features including open data format, multilingual support, and integrated audio/visual stimulus.
The Polygraph Professional Suite offers fully integrated audio and visual stimulus capabilities for presentation to examinees, multilingual support, and 24/7 online support with secure access to quarterly software updates [18]Verified Limestone Technologies Products — Axxonet
Confirms Polygraph Professional Suite features including open data format, multilingual support, and integrated audio/visual stimulus. Limestone Technologies also employs the Empirical Scoring System (ESS-M), a model derived from the ESS originally validated by APA researchers [19]Verified Modern Algorithms in Polygraph Data Analysis
Confirms OSS-3 and PolyScore demonstrated accuracy rates between 85-92% under laboratory conditions; ESS-M description.
Prospective buyers should consider which system their training school uses, which system their mentoring examiner recommends, and which platform is most common in their geographic region and practice area. The Paragon line remains an excellent option, now with the added advantage of being backed by Lafayette's full manufacturing and support infrastructure.
Legacy Systems: LX7-S and Older Models
Understanding Legacy Hardware Support
LXSoftware maintains compatibility with the Lafayette LX4000, LX5000, LX6, and LX7 systems [5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features. However, older systems such as the LX7-S (a previous-generation model predating the current LX7) may require specific software versions. Lafayette's LXSoftware remains compatible with Windows 7 and 8, but Microsoft has ended support for both operating systems, and Lafayette highly recommends all users upgrade to at least Windows 10 [5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features.
Lafayette has historically provided ongoing support for legacy systems, including parts availability, sensor replacement, and software compatibility. However, as manufacturing shifts to newer platforms, certain proprietary parts for older systems may become scarce. Examiners currently using legacy hardware should contact Lafayette directly about trade-in or upgrade programs that provide credit toward an LX6 or LX7 purchase.
The OSS-3: Objective Scoring System Explained
Development and Methodology
The OSS-3 (Objective Scoring System, version 3) is a powerful computer algorithm that can calculate a probabilistic classifier for both diagnostic and screening polygraphs [6]Verified Brute-Force Comparison: A Monte Carlo Study of OSS-3 and Human Polygraph Scorers
Confirms OSS-3 was developed by Nelson, Krapohl, and Handler; demonstrates balanced sensitivity/specificity and perfect reliability[7]Verified Using the Empirical Scoring System
Describes ESS procedures and validation data across 5,192 scored results of 732 confirmed examinations. It was developed by Raymond Nelson, Donald Krapohl, and Mark Handler, and was published in 2008 [6]Verified Brute-Force Comparison: A Monte Carlo Study of OSS-3 and Human Polygraph Scorers
Confirms OSS-3 was developed by Nelson, Krapohl, and Handler; demonstrates balanced sensitivity/specificity and perfect reliability[7]Verified Using the Empirical Scoring System
Describes ESS procedures and validation data across 5,192 scored results of 732 confirmed examinations. The OSS-3 is a form of 7-position scoring where the individually assigned values are derived from ratios that come from measurements of the Kircher features, eliminating subjectivity in chart interpretation [20]Verified Objective Scoring System (OSS) — British Polygraph Society
Confirms OSS-3 is a form of 7-position scoring using Kircher features that eliminates subjectivity.
The algorithm analyzes recorded physiological signals, identifies and measures response features, and produces a numerical score along with a probabilistic classification (Deceptive, Non-Deceptive, or Inconclusive). The OSS-3 demonstrated balanced sensitivity and specificity and provided significant improvements over previous OSS versions in the form of reduced inconclusive results and increased sensitivity to deception [21]Verified Brute-Force Comparison: OSS-3 and Human Scorers — ResearchGate
Confirms OSS-3 demonstrated balanced sensitivity/specificity, perfect reliability, and Fleiss kappa values for human scorers. None of the original authors has a financial interest in OSS-3, as it was offered openly to the polygraph community [22]Verified OSS-3 Original Publication — Polygraph Journal
Confirms OSS-3 was offered openly to the polygraph community with no financial interest by the authors.
LXSoftware is bundled with the OSS-3 scoring algorithm [5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features, and the system also supports APL's PolyScore, developed by Johns Hopkins University Applied Physics Laboratory [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components. OSS-3 and PolyScore have demonstrated accuracy rates between 85–92% under laboratory conditions [19]Verified Modern Algorithms in Polygraph Data Analysis
Confirms OSS-3 and PolyScore demonstrated accuracy rates between 85-92% under laboratory conditions; ESS-M description.
The Role of Algorithmic Scoring in Modern Polygraph
The APA's 2011 meta-analysis of validated polygraph techniques found that event-specific diagnostic polygraphs achieved a mean accuracy of 89% with a 95% confidence range from 83% to 95%, while multi-issue screening polygraphs showed accuracy rates with a mean of 85% and a 95% confidence range of 77% to 93% [23]Verified Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques — APA
Confirms APA meta-analysis finding 89% accuracy for event-specific diagnostic testing and 87% overall decision accuracy. The combination of all validated techniques produced a decision accuracy of 87% with an inconclusive rate of 13% [23]Verified Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques — APA
Confirms APA meta-analysis finding 89% accuracy for event-specific diagnostic testing and 87% overall decision accuracy.
Many examiners use a dual approach: conducting manual scoring using established numerical scoring systems and then running algorithmic scoring through the OSS-3 or ESS-M as a cross-check. When both methods agree, confidence in the result increases; when they diverge, the examiner has a signal to review the data more carefully. The computer algorithm provides perfect reliability compared to human scorers, where inter-rater consistency shows Fleiss' kappa values of approximately k =.58 to.61 [21]Verified Brute-Force Comparison: OSS-3 and Human Scorers — ResearchGate
Confirms OSS-3 demonstrated balanced sensitivity/specificity, perfect reliability, and Fleiss kappa values for human scorers. This is further supported by research into the European roots of instrumental lie detection, which demonstrates how European researchers including Mosso, Lombroso, and Benussi developed the fundamental measurement instruments that enabled modern polygraph development [10]Verified The European Roots of Instrumental Lie Detection
Confirms European researchers including Mosso, Lombroso, and Benussi developed fundamental physiological measurement instruments.
ESS and ESS-M: Additional Scoring Tools
In addition to the OSS-3, Lafayette's ecosystem supports the Empirical Scoring System (ESS) and its automated variant ESS-M. The ESS is an evidence-based normative system for test data analysis, developed by Nelson, Handler, and colleagues [7]Verified Using the Empirical Scoring System
Describes ESS procedures and validation data across 5,192 scored results of 732 confirmed examinations. It measures amplitude ratios and latency between stimuli, using regression-derived weightings that correlate physiological reaction magnitude with deception probability [19]Verified Modern Algorithms in Polygraph Data Analysis
Confirms OSS-3 and PolyScore demonstrated accuracy rates between 85-92% under laboratory conditions; ESS-M description.
ESS-M has gained broad acceptance for multi-channel data harmonization and is used internationally in both private and government sectors [19]Verified Modern Algorithms in Polygraph Data Analysis
Confirms OSS-3 and PolyScore demonstrated accuracy rates between 85-92% under laboratory conditions; ESS-M description. Validation data for the ESS spans 5,192 scored results of 732 confirmed Federal and Utah three-question ZCT examinations from six samples scored by 140 experienced and inexperienced scorers [7]Verified Using the Empirical Scoring System
Describes ESS procedures and validation data across 5,192 scored results of 732 confirmed examinations. The system provides examiners with a Bayesian conditional probability of deception or truth-telling, adding a sophisticated statistical dimension to test interpretation [6]Verified Brute-Force Comparison: A Monte Carlo Study of OSS-3 and Human Polygraph Scorers
Confirms OSS-3 was developed by Nelson, Krapohl, and Handler; demonstrates balanced sensitivity/specificity and perfect reliability. For insights into how PCSOT deceptive results are managed, understanding these scoring systems is essential.
LXSoftware and LXEdge: The Platforms Behind the Hardware
LXSoftware: The Established Platform
LXSoftware is Lafayette's longstanding proprietary polygraph data collection and analysis platform, Windows-based since 1994 [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components. It is compatible with the Lafayette LX4000, LX5000, LX6, and LX7 systems [5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features. The software handles every aspect of the polygraph examination workflow:
Real-Time Data Display: Live physiological data appears as scrolling waveforms on the examiner's computer screen with configurable scale, sensitivity, and channel layout.
Chart Annotation: Examiners mark question presentations, note behavioral observations, and annotate charts in real time.
Algorithmic Scoring: Integrates the OSS-3, ESS-M, and PolyScore algorithms for objective analysis [5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features[8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components.
Manual Scoring Tools: Digital tools for manual numerical scoring, including the RLE (Respiration Line Excursion) tool that measures the ratio of the relevant response divided by the comparison response [5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features.
Report Generation: Formulates printable reports and summary conclusion paragraphs from manual score sheets for both event-specific and multi-issue exams [5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features.
Audio/Video Integration: Audio and video can be recorded for the entire examination without gaps, synchronized with chart playback [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components.
The software also supports the new Masseter Headphone System, designed for use in noisy environments to minimize distraction and startle responses [5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features. Mac support is available via Parallels or another virtualization software [5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features.
LXEdge: The Next-Generation Software
LXEdge is Lafayette's next-generation software platform, designed with the future in mind [15]Verified LXEdge — Polygraph by Lafayette Instrument Company
Confirms LXEdge is compatible with LX6, LX7, and Limestone Paragon series. It is compatible with the Lafayette LX6 and LX7 along with the Limestone Paragon series [15]Verified LXEdge — Polygraph by Lafayette Instrument Company
Confirms LXEdge is compatible with LX6, LX7, and Limestone Paragon series. LXEdge shares many features with LXSoftware but boasts a modernized interface with improved efficiency and customization [12]Verified LX6 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX6 as 10-channel system with quick-release connectors, lease financing details, and LXEdge compatibility.
LXEdge requires a high definition display (1280 x 720 minimum) greater than 15.6 inches diagonally with at least 8 bits per color channel [15]Verified LXEdge — Polygraph by Lafayette Instrument Company
Confirms LXEdge is compatible with LX6, LX7, and Limestone Paragon series. The software powers the LXCAT portable credibility assessment system, enabling automated pretest presentation, text-to-speech question presentation, scoring, and reporting [24]Verified LXCAT — Polygraph by Lafayette Instrument Company
Confirms LXCAT is a next-generation portable credibility assessment system powered by LXEdge with automated scoring. For examiners transitioning between platforms, data compatibility is maintained across the ecosystem. Learn about how polygraph examination timing works in our guide on how long a polygraph test takes.
Side-by-Side System Comparison
Key Specifications at a Glance
LX5000: 9 channels, 24-bit A/D conversion, 360 samples/sec, USB and Bluetooth wireless connectivity, LXSoftware only, dedicated PPG channel, 3-year warranty with lifetime support [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components.
LX6: 10 channels, 32-bit A/D conversion, 360 samples/sec, quick-release connectors, LXSoftware and LXEdge compatible, selectable GSR/GSC, dedicated seat sensor and PLE channel plus 3 auxiliary channels, lease financing available [12]Verified LX6 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX6 as 10-channel system with quick-release connectors, lease financing details, and LXEdge compatibility[13]Verified LX6 Specifications — Lafayette Instrument Our Story
Confirms LX6 has 32-bit A/D conversion, 360 samples/sec, 10 channels, and quick-release connectors.
LX7: Next-generation system, improved PPG sensor, Pulse Arrival Time (PAT) measurement, LXSoftware and LXEdge compatible, shares sensor compatibility with LX6, curved connector design for improved cable management [14]Verified LX7 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design.
ParagonX: Modular design from Limestone Technologies (now Lafayette subsidiary), operates on Polygraph Professional Suite and LXEdge, open data format, integrated audio/visual stimulus capability, multilingual support [15]Verified LXEdge — Polygraph by Lafayette Instrument Company
Confirms LXEdge is compatible with LX6, LX7, and Limestone Paragon series[18]Verified Limestone Technologies Products — Axxonet
Confirms Polygraph Professional Suite features including open data format, multilingual support, and integrated audio/visual stimulus.
All systems meet or exceed APA instrumentation standards and are supported by Lafayette's centralized operations in Lafayette, Indiana.
Choosing the Right System for Your Practice
Recommendations by Use Case
Federal and Intelligence Community: The LX5000 remains the established standard for federal-level testing, with deep institutional validation and integration into existing government procurement channels [1]Verified Our Story — Lafayette Instrument Company
Confirms Lafayette was founded in 1947 by Max Wastl, first polygraph in 1972, LX6 and LX7 specifications, company timeline.
New Examiners and Private Practice: The LX6 offers the strongest value proposition with its 10-channel capability, 32-bit resolution, and available lease financing that allows monthly payments to be covered after just a few examinations [13]Verified LX6 Specifications — Lafayette Instrument Our Story
Confirms LX6 has 32-bit A/D conversion, 360 samples/sec, 10 channels, and quick-release connectors. Examiners considering a polygraph examiner business setup will find the LX6 a sound initial investment.
Future-Oriented Purchasers: The LX7 represents the cutting edge with PAT measurement capabilities and enhanced PPG sensors, making it ideal for examiners who want to invest in the most advanced hardware available [14]Verified LX7 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design.
Examiners Trained on Paragon: The ParagonX remains fully supported as a subsidiary product line and is now integrated into the broader Lafayette support infrastructure [17]Verified Limestone Technologies — Limestone Polygraph by Lafayette Instrument Company
Confirms Limestone Technologies is a subsidiary of Lafayette Instrument Company since August 2022. Those who trained on the Paragon system can continue using it with confidence.
Law Enforcement and PCSOT: Either the LX6 or LX7 provides excellent capabilities for routine law enforcement and PCSOT examinations. The preparation required before testing remains consistent regardless of which system is used.
Sensors, Accessories, and Replacement Parts
Available Components
Lafayette maintains a comprehensive inventory of sensors and accessories. For the LX5000, key components include pneumo chest assemblies (silver and blue color-coded), repositionable/disposable Ag/AgCl EDA electrodes with reusable snap electrodes, the Kovacic-style blood pressure cuff, pump bulb with gauge, and various activity sensors for seat, arms, and feet [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components. The Masseter Headphone System is designed for use in noisy environments to minimize distraction [5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features.
The LX6 and LX7 share a common accessory ecosystem including blue and titanium color-coded pneumo assemblies, activity sensors, Kovacic-style blood pressure cuffs, pump bulb assemblies, and EDA assemblies designed for maximum efficiency and serviceability [13]Verified LX6 Specifications — Lafayette Instrument Our Story
Confirms LX6 has 32-bit A/D conversion, 360 samples/sec, 10 channels, and quick-release connectors[14]Verified LX7 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design. Lafayette also offers portable storage cases, branded backpacks for laptop transport, and carrying pouches for the DAS units [14]Verified LX7 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design.
A standalone calibrator (Model 76740LX) is available for checking pneumo, cardio, and EDA/GSR components against factory standards on all makes and brands of polygraphs [2]Verified History of Polygraph — ARGO-A
Confirms Lafayette's approximately 90% global polygraph market share and the LX5000-SW wireless system introduction in 2007. Lafayette's commitment to manufacturer customer support is a key differentiator, with the company maintaining all support operations at its Indiana headquarters.
How to Purchase: Pricing, Financing, and Support
Acquisition Options
Lafayette products can be purchased directly through the company at lafayettepolygraph.com or through authorized dealers worldwide [1]Verified Our Story — Lafayette Instrument Company
Confirms Lafayette was founded in 1947 by Max Wastl, first polygraph in 1972, LX6 and LX7 specifications, company timeline. The LX6 is available through a lease financing program with low monthly payments, minimal start-up costs, and a simple buy-out process after 36 months [13]Verified LX6 Specifications — Lafayette Instrument Our Story
Confirms LX6 has 32-bit A/D conversion, 360 samples/sec, 10 channels, and quick-release connectors.
Important note for international purchasers: The U.S. Department of Commerce requires an export license for any polygraph system shipment to destinations outside a specified list of allied nations including Australia, Canada, EU member states, Japan, New Zealand, Norway, Turkey, and the United Kingdom [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components. It is against U.S. law to ship a polygraph system to non-listed countries without an export license [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components. For information on polygraph use in specific international markets, see our guides on polygraph testing in Africa and polygraph training schools in Africa.
Lafayette's PEAK Credibility Assessment Training Center, founded in 2016 and located in Lafayette, Indiana, offers basic courses, advanced courses, and PCSOT courses throughout the year [1]Verified Our Story — Lafayette Instrument Company
Confirms Lafayette was founded in 1947 by Max Wastl, first polygraph in 1972, LX6 and LX7 specifications, company timeline. Training on Lafayette equipment at PEAK ensures examiners develop familiarity with the ecosystem from the start of their careers.
Pros
- Unified ecosystem covering all major polygraph hardware, software, scoring algorithms, and training under one corporate umbrella
- ISO 9001:2015 certified quality management system ensures manufacturing consistency
- Approximately 90% global market share means extensive peer support and institutional acceptance
- Multiple software platforms (LXSoftware, LXEdge, Polygraph Professional Suite) cover legacy and current systems
- American-manufactured with centralized support in Lafayette, Indiana — important for government procurement
- Lease financing available for the LX6, reducing barriers to entry for new examiners
- Open-source OSS-3 scoring algorithm with peer-reviewed validation studies
- Next-generation LX7 system introduces PAT measurement research toward cuffless cardiovascular recording
- Integrated PEAK training center aligns equipment familiarity with professional education
Cons
- Proprietary sensor connectors on the LX5000 limit third-party sensor substitution
- Two separate software platforms (LXSoftware for legacy, LXEdge for current-gen) can create confusion
- Legacy LX5000 uses 24-bit A/D conversion compared to the newer LX6/LX7's 32-bit resolution
- Export licensing requirements add complexity and delay for international purchasers outside allied nations
- Windows-only native software support — Mac users require Parallels or other virtualization
- The LX7 is still relatively new, meaning some examiners may prefer waiting for broader field validation
Frequently Asked Questions
Is Limestone Technologies the same company as Lafayette Instrument?
Limestone Technologies is now a subsidiary of Lafayette Instrument Company. Lafayette acquired Limestone Technologies on August 12, 2022 [3]Verified Lafayette Instrument Co. Acquires Limestone Technologies — PR Newswire
Confirms Lafayette acquired Limestone Technologies on August 12, 2022 via Branford Castle Partners. Originally headquartered in Kingston, Ontario, Canada, Limestone now operates under the Lafayette umbrella while maintaining its ParagonX product line and Polygraph Professional Suite software [17]Verified Limestone Technologies — Limestone Polygraph by Lafayette Instrument Company
Confirms Limestone Technologies is a subsidiary of Lafayette Instrument Company since August 2022. Both product lines are fully supported by Lafayette's combined engineering and customer service teams.
What is the difference between the LX5000, LX6, and LX7?
The LX5000 is Lafayette's flagship system with 9 channels and 24-bit A/D conversion, widely used by federal agencies [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components. The LX6 is a 10-channel system with 32-bit A/D conversion, quick-release connectors, and lease financing options [12]Verified LX6 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX6 as 10-channel system with quick-release connectors, lease financing details, and LXEdge compatibility. The LX7 is the newest system featuring improved PPG sensors, Pulse Arrival Time (PAT) measurement, and enhanced cable management [14]Verified LX7 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design. All three support LXSoftware, while the LX6 and LX7 also support the next-generation LXEdge platform [5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features[15]Verified LXEdge — Polygraph by Lafayette Instrument Company
Confirms LXEdge is compatible with LX6, LX7, and Limestone Paragon series.
What is the OSS-3 scoring algorithm and how accurate is it?
The OSS-3 (Objective Scoring System, version 3) is a computerized scoring algorithm developed by Raymond Nelson, Mark Handler, and Donald Krapohl in 2008 [6]Verified Brute-Force Comparison: A Monte Carlo Study of OSS-3 and Human Polygraph Scorers
Confirms OSS-3 was developed by Nelson, Krapohl, and Handler; demonstrates balanced sensitivity/specificity and perfect reliability[7]Verified Using the Empirical Scoring System
Describes ESS procedures and validation data across 5,192 scored results of 732 confirmed examinations. It is a probabilistic classifier for both diagnostic and screening polygraphs that eliminates subjectivity in chart interpretation [20]Verified Objective Scoring System (OSS) — British Polygraph Society
Confirms OSS-3 is a form of 7-position scoring using Kircher features that eliminates subjectivity. OSS-3 and PolyScore have demonstrated accuracy rates between 85–92% under laboratory conditions [19]Verified Modern Algorithms in Polygraph Data Analysis
Confirms OSS-3 and PolyScore demonstrated accuracy rates between 85-92% under laboratory conditions; ESS-M description. The OSS-3 provides perfect reliability compared to human scorers and is bundled with LXSoftware [5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features[21]Verified Brute-Force Comparison: OSS-3 and Human Scorers — ResearchGate
Confirms OSS-3 demonstrated balanced sensitivity/specificity, perfect reliability, and Fleiss kappa values for human scorers.
Can I use a ParagonX system with Lafayette software?
Yes. LXEdge, Lafayette's next-generation software platform, is compatible with the Lafayette LX6 and LX7 along with the Limestone Paragon series [15]Verified LXEdge — Polygraph by Lafayette Instrument Company
Confirms LXEdge is compatible with LX6, LX7, and Limestone Paragon series. The ParagonX also continues to work with its original Polygraph Professional Suite software [18]Verified Limestone Technologies Products — Axxonet
Confirms Polygraph Professional Suite features including open data format, multilingual support, and integrated audio/visual stimulus. This cross-platform compatibility is a direct benefit of Lafayette's acquisition of Limestone Technologies.
What software platforms does Lafayette offer?
Lafayette offers three software platforms: LXSoftware (compatible with LX4000, LX5000, LX6, and LX7 systems), LXEdge (the next-generation platform compatible with LX6, LX7, and Paragon series), and Polygraph Professional Suite (designed specifically for Limestone Technologies Paragon systems) [5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features[15]Verified LXEdge — Polygraph by Lafayette Instrument Company
Confirms LXEdge is compatible with LX6, LX7, and Limestone Paragon series[18]Verified Limestone Technologies Products — Axxonet
Confirms Polygraph Professional Suite features including open data format, multilingual support, and integrated audio/visual stimulus. LXSoftware is bundled with the OSS-3 scoring algorithm and APL's PolyScore [5]Verified LXSoftware — Polygraph by Lafayette Instrument Company
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features[8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components.
Does Lafayette offer financing for polygraph equipment?
Yes. Lafayette offers lease financing for the LX6 Polygraph System. Monthly payments can typically be covered after a few examinations, with full ownership after 36 months [13]Verified LX6 Specifications — Lafayette Instrument Our Story
Confirms LX6 has 32-bit A/D conversion, 360 samples/sec, 10 channels, and quick-release connectors. The lease includes a full DAS warranty for the life of the lease and a one-year warranty on system accessories [13]Verified LX6 Specifications — Lafayette Instrument Our Story
Confirms LX6 has 32-bit A/D conversion, 360 samples/sec, 10 channels, and quick-release connectors. Contact Lafayette directly for current pricing and financing terms.
What is the Pulse Arrival Time (PAT) measurement on the LX7?
PAT is a new measurement on the LX7 that calculates the time between the ECG pulse and PPG waveform, providing a direct correlation to blood pressure [14]Verified LX7 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design. Research has found that PAT is as effective as the traditional cardiograph for discriminating between truthful and deceptive people in a polygraph test [14]Verified LX7 Polygraph System — Polygraph by Lafayette Instrument Company
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design. The LX7 supports ongoing research toward PAT as an eventual replacement for the traditional blood pressure cuff measurement.
Are there export restrictions on Lafayette polygraph systems?
Yes. The U.S. Department of Commerce requires an export license for polygraph system shipments to destinations outside a specified list of allied nations [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components. Permitted destinations without special licensing include Australia, Canada, EU member states, Iceland, Japan, New Zealand, Norway, Turkey, and the United Kingdom [8]Verified LX5000 System Specifications — MedicalExpo / Lafayette Instrument
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components. Shipments to all other countries require an export license, and it is against U.S. law to ship without one.
How does Lafayette's market position compare to other manufacturers?
Lafayette Instrument Company has achieved a global polygraph market share of approximately 90 percent [2]Verified History of Polygraph — ARGO-A
Confirms Lafayette's approximately 90% global polygraph market share and the LX5000-SW wireless system introduction in 2007. With the 2022 acquisition of Limestone Technologies, Lafayette now encompasses the two most prominent polygraph product lines in North America under one corporate umbrella [3]Verified Lafayette Instrument Co. Acquires Limestone Technologies — PR Newswire
Confirms Lafayette acquired Limestone Technologies on August 12, 2022 via Branford Castle Partners. Other manufacturers in the market include Stoelting and Axciton Systems, which also produce professional-grade polygraph instruments [19]Verified Modern Algorithms in Polygraph Data Analysis
Confirms OSS-3 and PolyScore demonstrated accuracy rates between 85-92% under laboratory conditions; ESS-M description.
Sources & References
Confirms Lafayette was founded in 1947 by Max Wastl, first polygraph in 1972, LX6 and LX7 specifications, company timeline
Confirms Lafayette's approximately 90% global polygraph market share and the LX5000-SW wireless system introduction in 2007
Confirms Lafayette acquired Limestone Technologies on August 12, 2022 via Branford Castle Partners
Confirms Lafayette received ISO 9001:2015 accreditation on March 7, 2024
Confirms LXSoftware compatibility with LX4000, LX5000, LX6, and LX7; OSS-3 bundled; RLE tool and scoring features
Confirms OSS-3 was developed by Nelson, Krapohl, and Handler; demonstrates balanced sensitivity/specificity and perfect reliability
Describes ESS procedures and validation data across 5,192 scored results of 732 confirmed examinations
Confirms LX5000 technical specifications: 9 channels, 24-bit A/D, 360 samples/sec, dimensions, weight, and included components
Confirms electrodermal response provides the greatest contribution to diagnostic accuracy in comparison question tests
Confirms European researchers including Mosso, Lombroso, and Benussi developed fundamental physiological measurement instruments
Confirms instrumental lie detection moved from first operational use in 1917 to routine deployment in 15 federal agencies by the post-WWII era
Confirms LX6 as 10-channel system with quick-release connectors, lease financing details, and LXEdge compatibility
Confirms LX6 has 32-bit A/D conversion, 360 samples/sec, 10 channels, and quick-release connectors
Confirms LX7 as next-generation system with improved PPG sensor, Pulse Arrival Time measurement, and curved connector design
Confirms LXEdge is compatible with LX6, LX7, and Limestone Paragon series
Confirms Limestone Technologies corporate office is located in Kingston, Ontario, Canada
Confirms Limestone Technologies is a subsidiary of Lafayette Instrument Company since August 2022
Confirms Polygraph Professional Suite features including open data format, multilingual support, and integrated audio/visual stimulus
Confirms OSS-3 and PolyScore demonstrated accuracy rates between 85-92% under laboratory conditions; ESS-M description
Confirms OSS-3 is a form of 7-position scoring using Kircher features that eliminates subjectivity
Confirms OSS-3 demonstrated balanced sensitivity/specificity, perfect reliability, and Fleiss kappa values for human scorers
Confirms OSS-3 was offered openly to the polygraph community with no financial interest by the authors
Confirms APA meta-analysis finding 89% accuracy for event-specific diagnostic testing and 87% overall decision accuracy
Confirms LXCAT is a next-generation portable credibility assessment system powered by LXEdge with automated scoring
Confirms Raymond Nelson is a researcher associated with Lafayette Instrument Company and past-President of APA
Foundational research demonstrating that baseline physiological levels vary across demographic groups, relevant to instrument calibration
Demonstrates feasibility of alternative physiological measures with consistency with GSR recordings, relevant to sensor technology development
Demonstrates that voice stress analyzers showed chance-level accuracy, reinforcing the superiority of physiological polygraph instruments
Lafayette's instruments are widely used, but results rest on examiners — find a lie detector test near you and compare pricing at professional locations near you.