What Thermalogic makes

Thermalogic Corporation designs, engineers, and manufactures built-to-order electronic temperature, humidity, and process controls and temperature sensors for OEMs and volume users. The work is custom by default: the company builds from a customer's drawings, sketches, or a plain description when off-the-shelf controls will not meet the spec, then supports the part through prototyping, production, and inventory over its life.

The catalog is organized into trademarked product lines that act as starting points for a custom build. Controls include TempGuard Microprocessor and TempGuard Analog (non-indicating microprocessor and analog controls), the Master Series (multi-zone, multi-function microprocessor controls for demanding applications), and Digitherm (indicating microprocessor controls available in 1/8 DIN and 4.3-inch and 7-inch touchscreen formats). On the measurement side, HumiSense covers relative-humidity transmitters and SureSignal covers temperature and humidity transmitters for industrial use. Temperature sensor assemblies are built with RTD, thermocouple, and thermistor elements in a range of sheaths, fittings, and lead types. The company also builds internet-enabled controls and transmitters with WiFi, Bluetooth, Ethernet, USB, and RS-232/RS-485 communications, written to a customer's protocol or its own.

Manufacturing is done in-house in Hudson, Massachusetts: the company assembles the electronic circuit boards, solders and seals the electronics, builds the sensors, and 100% tests every unit before it ships. That test-everything policy and a 4-year limited warranty are the quality claims the company leads with.

Where the controls end up

Thermalogic sells into a broad set of equipment categories rather than a single vertical. Named industries on its own site include environmental equipment, liquid chillers, industrial HVAC, heat-treat equipment, food-processing equipment, military HVAC, medical, lab and testing equipment, packaging equipment, railcar HVAC, semiconductor processing equipment, industrial ovens, and commercial incubators.

The company describes its own position plainly. In a 2023 WCVB feature, President Joe Grein said Thermalogic operates as a third-tier subcontractor whose parts are embedded inside other companies' finished products, "even though they operate as a third tier sub-contractor, other products can't get to market without them." The same report named the end applications its controls reach: MBTA rail car air-conditioning units, food-service ovens (Pizza Hut was cited), medical diagnostics and blood analyzers, railroads, and carpet cleaners. These are the fields Thermalogic's controls go into, not published direct-customer contracts, but they show the kind of precision-dependent equipment the company serves. For a buyer mapping a bill of materials, that is the role a controls specialist plays: a component that a finished product cannot ship without.

Ownership and history

Thermalogic was founded in 1971 by Lou Grein and John DuBois, originally inside the old Waltham Watch Factory in Waltham, Massachusetts. It marked its 50th anniversary in 2021. The company moved to its current 25,000-square-foot facility in Hudson, Massachusetts in 1997, where the full range of design, engineering, and manufacturing is performed.

The business remains independent and family-owned across two generations. Jeremy DuBois, son of co-founder John DuBois, is Chief Executive Officer; Joe Grein, son of co-founder Lou Grein, is President; and Eric Lundberg is Vice President. Thermalogic identifies itself as a small business and publishes a small-business statement among its compliance documents. As a component maker deep in the supply tiers, its scale is modest by design: a focused engineering-and-build shop rather than a high-volume commodity manufacturer.

Certifications and quality

Thermalogic does not claim a third-party ISO 9001, AS, or IATF certificate on its site. Its quality posture instead rests on a published Quality Assurance Manual (dated December 2023), a policy of 100% functional testing before shipment, and a Blanket Certificate of Compliance and Calibration. On materials and trade compliance, the company publishes RoHS-3, REACH, conflict-minerals (EICC), California Proposition 65, Persistent Organic Pollutants, and NAFTA Certificate of Origin statements. Buyers who require a formal registered quality management system should confirm current status directly with the company.

Frequently asked questions

What does Thermalogic make?

Thermalogic makes built-to-order electronic temperature, humidity, and process controls and temperature sensors for OEMs and volume users. Product lines include TempGuard, Master Series, and Digitherm controls, HumiSense and SureSignal transmitters, and RTD, thermocouple, and thermistor sensor assemblies. It also builds internet-enabled and touchscreen controls to customer specification.

Who owns Thermalogic?

Thermalogic is an independent, family-owned business founded in 1971 by Lou Grein and John DuBois. It is now run by the founders' sons: Jeremy DuBois is CEO and Joe Grein is President, with Eric Lundberg as Vice President.

Where is Thermalogic located?

Thermalogic is headquartered at 22 Kane Industrial Drive, Hudson, Massachusetts 01749, in a 25,000-square-foot facility it has occupied since 1997. The company was originally founded in Waltham, Massachusetts inside the old Waltham Watch Factory.

Who are Thermalogic's customers?

Thermalogic sells to OEMs and volume users across environmental equipment, HVAC, heat-treat, food processing, medical and lab equipment, packaging, railcar HVAC, semiconductor processing, and industrial ovens. As a third-tier subcontractor it does not publish a customer list; a 2023 WCVB report named end applications including MBTA rail car air conditioning, food-service ovens, and medical diagnostics equipment.

How long has Thermalogic been in business?

Thermalogic has been in business for 55 years, founded in 1971 and marking its 50th anniversary in 2021. It has operated from its Hudson, Massachusetts facility since 1997.

What certifications does Thermalogic hold?

Thermalogic publishes a Quality Assurance Manual (December 2023), a Blanket Certificate of Compliance and Calibration, and RoHS-3, REACH, conflict-minerals, Proposition 65, and NAFTA-origin compliance statements, and it 100% tests every unit before shipment. It does not claim a third-party ISO, AS, or IATF certificate on its website; confirm current quality-system status with the company.

Last verified September 28, 2026. Is this your company? Request a correction.