`BIS' Standard.   The product is covered by Bureau of Indian Standards vide IS 3017-1985
(Specification for Thermostat for use with Electric Water Heaters).

`ISI' MARKING LICENSE. Our stem thermostats of 25-75 °C, having stem lengths of 175 mm & 275 mm are covered under Marking License No. CM/L - 7059270.

PRINCIPLE OF OPERATION. Differential linear thermal expansion available from a
combination of stem of brass tube (high thermal expansion alloy) and nickel-iron wire
(very low thermal expansion alloy) is used to operate a high-precision micro-gap switch. Switch contacts open when temperature of brass stem exceeds the set temperature & close when temperature drops by the differential temperature.

As the mechanism is operated by linear thermal expansion, tolerance on operating temperature and differential temperature improves with increase in stem length.

CONSTRUCTION. Switch is provided with heavy-duty silver cadmium oxide contacts.
Contact spring is made of Beryllium Copper & properly heat-treated. Steatite component is used for insulation between stem & live terminals. Extra large brass terminal pillars are used. Switch base is made of electrical grade material. Brass tube and nickel-iron wire are brazed together using silver alloy.

APPLICATION. These are designed for use in electric water heaters & geysers, water baths,
oil baths, Space Heating in Switchboards and Panels and similar other applications where temperature need to be maintained automatically.

 Note:  Manufacturer reserves the right to change specifications, design & materials of the product   without notice.