Hi-Endurance Switching, Sensing
& Linear Position Sensors

Electromechanical Temperature Switch Products

Temperature switches, temp switches & thermal switches by CPI
CPI’s line of temperature controlled switches can operate up to 1750F

Demanding military and industrial temperature control switch applications continue to be served by precisely engineered electromechanical temperature switches.  While some applications have gone the way of sensors and controllers, there are distinct advantages to electromechanical temperature control switches.  Primary among these advantages are:

  1. Completely self contained temperature detection and switching devices.
  2. Switches are passive devices and therefore require no power.
  3. Capable of precise operation at high temperature with tight set point tolerances.
  4. Extremely reliable, field proven technology.
  5. Can handle high current switching applications.
  6. No external control system is required as in the case of remote sensors/switching.
  7. Cost effective.

CPI has been designing and evolving temperature switch technology since it built its first thermal switches for the military in 1946. Our off the shelf products are complemented by a design team that develops switches for OEM’S across the country providing deep expertise, and full documentation and testing of your custom solution.

Temperature Switch Technologies

Temp switches developed by CPI fall into 3 primary classes, each with differing characteristics that make them excellent in a wide variety of applications.

SnapDisc Temperature Switches

Temperature switches for military vehicles Bimetallic Snap Disc – In our SnapStat Thermal Switch series, contact movement is achieved using a bimetallic snap disc. Snap action provides shock and vibration immunity and a broader temperature differential over an operating temperature range from 0F to 300F (-17.8C to 148.9C) degrees. Switch configurations include surface mount without probe, surface mount with probe, thread mount, clamp mount, hermetically sealed, and dual setpoint. The various switch applications including over-temperature on air compressors, distilling machines, food extruders, escalators, engine coolant, and elevators.

PlugStat Temperature Switches

Temperature Switches for Energy Bimetal Devices – These devices are slow make and break devices which provide tight tolerance temperature sensing over a small range. These correspond to our PlugStat Series of switches with a temperature range of 0F to 650F (-17.8C to 343.3C) degrees. These switches also come in a wide variety of form factors including solder terminals, glass sealed connectors, with integral wire leads, and with dual setpoints.  Plugstats are used extensively in aircraft ECS, plastic extruders, wind turbines, and various military vehicle systems.

Rod and Tube Temp Switch

Temperature Switches for Refineries Rod And Tube – This type of temperature switch operates by utilizing differences in coefficients of expansion of two materials – the rod and the tube.  Since the external tube is the high expanding element, these products (our X, AB, and W Series) offer outstanding response times. They also have the highest set point capability operating from 0F to 1750F (-17.8C to 954.4C).  Applications include aircraft engine overtemp, refinery process control, railroad switch flame detection, stack scrubber temperature monitoring and turbine exhaust monitoring, and brake over temp indication on large construction equipment.


Customizing Your OEM Thermal Switch Solution

Correlating precise production calibration conditions at the factory with field conditions on OEM equipment is not always a matter of just applying a formula.  For CPI Temperature switches to consistently perform as expected it is critical that all electrical and thermal parameters be specified, and that all operating scenarios be identified up front and tested.

The following are parameters to consider in your customization of a thermal switching solution

Thermal Parameters

Electrical Parameters

Other Specs

Set Point Switch Action (close on rise, open on rise, SPDT, make before break) Electromechanical Endurance
Tolerance Current Terminations
Differential (Hysteresis) Voltage Rating Mounting/probe options (surface mount, probe, bulkhead)
Probe Overshoot/Undershoot Type of load Environmental considerations


At CPI, our engineering team will work directly with OEM’s to design, qualify, and produce reliable temperature switches that meet your requirements every time.


Please contact CPI sales today (973)887-9400 to discuss your custom temperature controlled switching application.

Make the switch to CPI today, we can help.

Make The "Switch" to CPI

If your momentary switch application demands high performance, we think you should demand CPI. Please call us today to speak with our engineering team about your needs.

(973) 887-9400