The following chart indicates some of the advantages and disadvantages of RTD’s and thermocouples.

THERMOCOUPLE RTD’S
Accuracy Limits of error wider than RTD Limits of error smaller than thermocouples
Ruggedness Excellent Sensitive to strain, shock, and pressure
Temperature -240° to 2300°C -128°C to 800°C
Size Can be as small as .01” sheath material, tip sensitive Size limited to 1/16”, temperature sensitive for length of bulb
Drift Should be checked periodically,higher than RTD’s 0.01 to 0.1°C per year, less drift than thermocouple
Resolution Must resolve millivolts per degree, lower signal to noise ratio Ohms per degree, much higher

signal to noise ratio than thermocouple

Cold Junction Reference Required Not required
Lead wire Must match lead wire calibration to thermocouple calibration Can use copper lead wire for extension wire
Response Can be made small enough for millisecond response time Thermal mass restricts time to seconds or more
Cost Low Higher than thermocouples

dpstar is the leading manufacturer and supplier of Thermocouple and RTD’s in Malaysia and  South East Asia.

Please send your enquiry to: info@dpstar.com.my.

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