Thermocouple vs RTD’s

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,	0.01 to 0.1°C per year, less drift than thermocouple
	higher than RTD’s
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.