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Electronics manufacturers representative for Ohio, PA, IN, MI, WV and KY

Serving OH, MI, IN, W. PA, WV and KY

Thermistors, Thermocouples, and RTD’s for Temperature Control Projects

Thermisters thermocouples rtds

Are you looking for more common sense? Along with a wide variety of electromechanical thermostats, there’s a whole world out there of temperature components that just sense.

By just sense, unlike thermostats that are sensing temperature AND opening/closing circuits accordingly, these sensors need some brains at the end of their wires to translate their reading into something that can be acted on and utilized.

Thermistors, thermocouples, and RTD’s are all sensor options that provide a resistance or voltage output, but what makes them different than other components, such as a resistor?

These sensors’ resistance and voltage outputs mean something, that when paired with electronics utilizing the corresponding RT (Resistance-Temperature) tables or lookup tables, base resistances and beta value’s, etc., let the system know what temperature the sensor is reading.

Common Sense Fig 7A GraphFor example, say you have a thermistor sensing the air temperature inside of a refrigerator. Someone leaves the door open too long so the air temperature starts increasing, thermistors (being NTC, or Negative Temperature Coefficient devices) “sense” this increase in air temperature by the reported resistance value decreasing. The electronics read this decrease in resistance and know the fridge is warming up, so it starts the cooling process to bring the temperature back down.

With this information…DING dinner’s ready, CRASH the ice-maker kicks on, or RUMBLE-RUMBLE the compressor in your fridge starts up!

Selco can help provide all the information you need to correlate these readings and get the most out of your sensors…want to get even more technology? Check out what electronic temperature controls or “brains” needed for your next temperature control project here.


We are honored to serve as a manufacturer’s rep for Selco. Selco’s wide range of temperature control products serve a variety of industries including appliance, HVAC, medical, telecommunications, food service, and instrumentation. Products include thermostats, NTC thermistors, thermal cut-offs, thermal protectors, knobs, precision electronic controls, high-bright LED lighting, panel instruments, and photocells.