TEMPERATURE MEASUREMENT

GSI offers a complete line of contacting type temperature measurement sensors for a broad range of temperature monitoring and control applications. 

Thermocouples and RTDs

Transmitters

Thermocouples and RTDs

Thermocouples are the most common, convenient, and versatile sensors to measure temperature. A thermocouple consists of a "hot" junction between two dissimilar metals, (usually wire) and a reference junction at the opposite end. Heating the hot junction produces a temperature gradient that generates a small voltage proportional to temperature. Through proper selection of lead wires, sheath material, and connection heads, thermocouples are suitable for temperature ranges from -300 F to 4200 F.

A resistance temperature detector (RTD) is composed of a metallic element whose change in resistance is a function of temperature. Common materials for this element are platinum, copper, and nickel. In operation a small excitation current is passed across the element and the voltage, which is proportional to resistance, is then measured and converted to units of temperature. Selection of a proper sheath material, and connection head allow RTD's to be operated over a temperature range of -150° F to 1400° F. 

Transmitters

Temperature transmitters convert thermocouple or RTD temperature sensors to a 4-20 mA signal utilized for transmitting signals long distances and interfacing to control and data acquisition systems.  Transmitters are available with local displays and hazardous area enclosures for field mounting.