Bi-Metallic Temperature Gauge

The Temperature is measured with a bimetal system inside the thermometer stem. The bimetal system consists of two metal strips bounded together that have different thermal expansion coefficients. Therefore, one strip will expand faster than the other causing the bimetal strip to curl in proportionate temperature. The bimetal system is helically wound and heat treated for long term stability. Temperature variations cause the bimetal strip to unwind or wind together, which in turn rotates the pointer.

Gas Filled Temperature Gauge

A Gas Expansion Thermometer is made of a cylindrical bulb filled with inert gases & uses the volume expansion of gases at temperature changes. Gas Pressure changes inside the bulb due to temperature changes are sensed by a special helical bourdon tube, which is connected to an amplifying device will give the pointer movement proportional to the temperature. The physical properties used will enable linear reading on the dial from the original to the full scale. When the reading is remote from the sensing point, a capillary is then used for transmission between the bulb and the thermometer head. Capillary armoring is common practice in industrial environments.

Mercury Filled Temperature Gauge

A Mercury Filled Thermometer is made of a cylindrical bulb filled with mercury & uses the volume expansion of gases at temperature changes. Mercury with Gas Pressure changes inside the bulb due to temperature changes are sensed by a special helical bourdon tube, which is connected to an amplifying device will give the pointer movement proportional to the temperature. The physical properties used will enable linear reading on the dial from the original to the full scale. When the reading is remote from the sensing point, a capillary is then used for transmission between the bulb and the thermometer head. Capillary armoring is common practice in industrial environments.