Open-thermistor temperature sensors use fused glass

Gems Sensors & Controlsvisit website


Open-thermistor temperature sensors use fused glassFused glass is key to providing the leak-proof operation of these new open thermistor-type temperature sensors from Gems Sensors & Control. The TM-950 Series temperature sensors utilise an open (exposed) thermistor design for faster response to temperature fluctuation than can be achieved with closed (encapsulated) designs. The TM-950 Series solves the sensed fluid leakage problem common with other open thermistor type sensors currently available. Originally designed for oil and refrigerants in HVAC and Chiller systems, TM-950 sensors can be used to monitor temperatures in any non-conductive fluid.

Product Engineer, Jim Dockendorff, explains: “TM-950 temperature sensors use an open (or exposed) design to place the ceramic thermistor in direct contact with sensed fluid. The open design is valued over encapsulated type sensors for their faster response time. The downside to most open thermistor sensors, however, is leakage through the housing where the thermistor leads pass through sensor housings, especially in pressured installations. In HVAC or Chiller systems this can cause significant maintenance and performance degradation issues. Gems TM-950 Series fuses glass inside the sensor housing, and uses inductive soldering around the thermistor leads to produce a hermetic seal. Leakage is eliminated while taking advantage of the quick responsiveness of an open, direct contact thermistor.”

TM-950 Series provide a standard referenced temperature sensing range of 32degF to 100degF (0degC to 38degC) and an over-exposure capability range of -40degF to +250degF (-40degC to +125degC). Any of a variety of thermistors may be utilised based on the temperature sensing profile required. Standard pressure rating is 450psig (31bar), with higher pressure capability available upon request. Wetted materials include zinc-plated steel, nickel-plated steel, Teflon, ceramic, tin, and soda lime glass. Standard termination is IP65, 18AWG, PTFE insulated flying leads.

More complete specifications, and dimensions for TM-950 Series temperature sensors and other Gems temperature sensors are available at

13 February 2014

Gems Sensors & Controlsvisit website
See all stories for this company
© Copyright 2006-14 The Engineering Network Ltd.