About KWJ

Company Timeline



Founded in 1993

KWJ Engineering was started in 1993 by Ken Johnson, after the sale of his company GasTech, to Thermo Electron in 1992.




Transducer Technology

KWJ merged with Transducer Technology, Inc., originally founded in 1999 by Dr. Joseph Stetter and specialized in nano-technology based sensors.


ECO Sensors

KWJ acquired Eco Sensors, Inc., the Santa Fe, NM based market leader in functional ozone detection and monitoring equipment for industrial uses. 


SPEC Sensors

SPEC Sensors LLC is founded to specialize in the sale and production of screen printed electrochemical gas sensors for air quality.




Today KWJ provides industrial gas sensors, personal protective instruments, pioneers new sensor technology with research and development, and offers advanced engineering services for custom projects.

Our Team of Engineers and Scientists

Joe Stetter – President / CTO

Mike Carter – Director of Research

Mel Findlay – Senior Principle Engineer

Mitchell Lee – Mechanical Engineer

Bennett Meulendyk – Senior Electrical Engineer

Gavin O’toole  – Firmware Engineer

Vinay Patel – Senior Sensor Engineer

David Peaslee – Senior Metrology Engineer

KWJ Management Team

President and CTO

PhD – University of Buffalo, Suny (Physical Chemistry, 1975)

For nearly 40 years, Dr. Stetter has been at the forefront of chemical sensor and associated technology as a leading researcher, entrepreneur, author, and educator.  In his early career, Dr. Stetter developed patented electrochemical sensors and the first electrochemical dosimeters for gas detection. Products he championed for personal protection and environmental monitoring that have saved lives, improved worker health, and personal well-being.  At the Illinois Institute of Technology, Dr. Stetter began his career as a life-long educator.  Dr. Stetter has been pivotal in establishing sensor research within industry and university settings and advancing the applications of nanotechnology in gas detection.

Dr. Stetter has founded several technology-based sensor companies, received numerous awards and published prolifically throughout his career.  With over 40 patents, his work is the foundation of many sensor and gas detection products still in use today.  At KWJ Engineering, Dr. Stetter not only continues to innovate and develop products for the social good, but also mentors a new generation of engineers and scientists.

General Manager

JD – Illinois Institute of Technology:  Chicago-Kent College of Law (2004)
BBA – University of Notre Dame (Business Administriation, 2001)  BS – Computer Applications

In addition to his role as General Manager of KWJ Engineering, Ed is also Co-Founder and General Manager of SPEC Sensors, LLC, whose advanced sensor technology originated from KWJ’s National Science Foundation grants.  KWJ and SPEC work closely together to produce sensors and instrument solutions for new and challenging gas sensing applications.  Ed also has experience as a corporate attorney and is licensed to practice law in Illinois.  Ed holds one patent for his work in advanced gas sensor technology.

Engineering Services

Director & Senior Sensor Engineer

MS, Chemical Engineering & Computer Science, 2001

For the past 15 years, Mr. Patel has been a vital part of the research and product development team, first at TTD and now at KWJ.  Mr. Patel began his career at the Illinois Institute of Technology in Chicago with the sensor research group, where he excelled at sensor development, characterization, processing and assembly.  At KWJ, Mr. Patel has been a leading researcher in chemical engineering and polymer technology as well as a sensor assembly process supervisor.  He has co-authored publications and is co-inventor on several patents in the areas of chemical sensors and their applications.  Mr. Patel has played a major role in several development projects in sensor design for both air and water monitoring and is at the forefront of product development including sensors for the Pocket CO and ozone product lines.  He also contributes to management and training of assemblers for both instruments and sensors.  His work in sensor metrology and process development is enabling KWJ to improve sensor performance and ramp up sensor production as well as miniaturize sensor configurations.

Senior Electrical Engineer


Research and Development

Director of Research

Ph.D. University of Texas at Austin (Chemistry, 1989)
M.B.A. University of Colorado – Denver (2003)

Dr. Michael Carter has been leading the research department at KWJ since 2010, innovating new solutions to gas detection problems, advancing research in gas sensing systems, and serving as a mentor for the research team.  He has led numerous successful Phase I and II SBIR programs and has commercialized advanced, SBIR-funded technology for air and water quality monitoring.  His current work focuses on the application of ionic liquids to gas sensing with printed amperometric sensors, development of wearable transdermal alcohol sensors, portable low-cost monitoring of heavy metals in water, and applications of environmental gas sensors.

Dr. Carter has been involved in physical and analytical electrochemistry, and ionic liquids research and development since the early 1980s.  He has over 22 years of experience in chemical sensor development as both a principal investigator and a group leader.  At Eltron Research and Development, Dr. Carter served as senior electrochemist, manager, and research fellow focusing on electrochemical analyzers, infrared and visible wavelength hazardous gas sensors, and chemical sensing applications of ionic liquids.   Dr. Carter is a prominent contributor in his field as a researcher, presenter, organizer, manager, and industry leader.  His interdisciplinary work is widely published and he has served as an editor for several Electrochemical Society Transactions volumes on chemical sensors.  Dr. Carter is a past Chair of the Sensor Division of the Electrochemical Society and is also a member of the American Chemical Society.  He holds four patents on chemical sensors, printed gas sensors, and ionic liquid technologies.  As the leading researcher at KWJ, Dr. Carter’s work is not only advancing gas detection, he is also helping to pioneer new product design.

Senior Principal Engineer

M.Sc. Environmental Chemistry / Env. Health Engineering  (Northwestern University, 1985)

Mr. Findlay has more than 25 years’ experience in environmental chemistry and analytical methods in air and water, with focus on the development of portable sensors and instrumentation. With roots in chemistry, but an engineering perspective and a passion for developing products to protect lives and health, Mr. Findlay excels at carrying technology from the R&D team through to manufacturing. He is co-inventor of the revolutionary “printed” electrochemical gas sensor, whose miniature size and low power requirements is enabling innovations in highly accurate air pollution monitoring for networks and wearable devices. 

Prior to KWJ, Mr. Findlay was with TSI Inc. for 10 years, where he was responsible for sensor selection, design and manufacture, and sampling design for a series of successful products, including the QTtrack® and IAQ-Calc® indoor air quality monitors, and the CACalc® and CombuCheck® combustion analyzers. Mr. Findlay first worked with Dr. Stetter while at Argonne National Laboratory, on a project to develop the first sensor-array based instrument, the CPS-100 “Chemical Parameter Spectrometer.” He is co-inventor on the patents for this instrument developed for the US Coast Guard and Drug Enforcement Agency.

Metrology Engineer

Ph.D.  Missouri University of Science and Technology (Experimental Physics, 2013)

Dr. David Peaslee has been a key member of the sensor research and development team for both KWJ Engineering and SPEC Sensors for the past several years.  His research in electrochemical modeling has been pivotal in improving the selectivity and accuracy of SPEC’s electrochemical sensors.  Prior to joining KWJ, Dr. Peaslee worked on electrochemical energy storage projects at NASA Ames and at the University of Missouri – St. Louis.  His work with ionic liquids and ionic gels at NASA Ames, led to a fundamental understanding of the potential to expand gas sensing into extreme temperature situations.

Dr. Peaslee was recently awarded his first two SBIR grants for Phase I projects focusing on air quality systems, “Low-Cost Wearable Device for Total Environment Health Monitoring” and  “Zero Power Electrochemical Formaldehyde Sensor with Novel Catalyst for Indoor Air Quality”, a project that led to the development of SPEC’s formaldehyde sensor.  Dr. Peaslee’s broad range of expertise has made him an invaluable asset to the KWJ and SPEC engineering team in both research and product design as well as custom engineering and support.

In Memory of Ken Johnson


“Ken was not only our best instrument engineer at KWJ but our mentor. He came to work every day, and half day on most Saturdays up until the last few months. Ken was a person of extremely high integrity in his engineering, business, and personal life. A true professional and also a visionary in seeing ways to integrate a plan for the future into the present activity. We all miss him dearly.”

Ken Johnson was the founder and owner of GasTech Inc. from 1971 until its sale to Thermo Electron in 1992. He started KWJ Engineering in 1993 as a provider of specialized gas detection instruments and systems. Earlier he was a principal of Johnson-Williams, Inc., which was acquired by Bacharach in 1965. He had full-time involvement in development, design and application of gas detection instrumentation since 1947, and Ken’s father developed the first modern combustible gas detector. Ken had a BSME from CalTech, an MSEE from Stanford, and was a Registered Mechanical Engineer in the State of California. He originated many of the concepts and features of gas detection instruments in use today, and was honored as a Fellow of ISA in 1992 for his life’s work in gas detection instrumentation.