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The SOR® temperature switch utilizes a vapor-pressure thermal system. Fluid vapor pressure changes predictably according to the influence of temperature on the sensing bulb. Process temperature changes cause proportional vapor pressure changes in the temperature sensing bulb that act on the diaphragm/ piston assembly to actuate and de-actuate a snap-action electrical switching element at discrete process temperatures. The instrument’s behavior is determined by the vapor pressure principle.

SOR Temperature Switch Working Principle

The SOR temperature switch consists of a pressure switch that has a sealed temperature sensing bulb attached directly to the pressure port. (An optional remote temperature sensing bulb can be connected to the pressure port with an armor-clad capillary.) The temperature sensing system is partially filled with a fluid. Process temperature changes cause proportional vapor pressure changes in the temperature sensing bulb that act on the diaphragm/piston assembly to actuate and deactuate a snap-action electrical switching element at discrete process temperatures. The instrument’s behavior is determined by the vapor pressure principle.

Basic models with direct and six-foot remote temperature bulbs. More specific application requirements can be met by selecting optional components, such as housings and electrical switching elements.

These switches utilize a Sensing Bulb-Range Designator combination to determine the adjustable range and type of sensing. 

Configuration choices are available for:

  1. Housing - To be used in different application conditions such as Explosion Proof or Weathertight
  2. Switching Element - for different AC/DC ratings and dead bands
  3. Thermowell - if required, available as a separate item
  4. Accessories - For miscellaneous such as Certificates, Special Coatings, Additional Tests

Specific application requirements can normally be met by selecting optional components, such as switching elements, diaphragm systems and pressure ports.

For more information, please download the Temperature Switches (Form CAT220) catalog