Keithley 2511 Temp Sensor free download

File name 2511 Temp Sensor.pdf

A G R E AT E R M E A S U R E O F C O N F I D E N C E Resistance temperature detectors (RTDs) RTDs measure temperature by monitor- ing changes in the electrical resistance of metal wires or films. The wire used is usu- ally platinum, although other metals, includ- ing nickel, a nickel/iron alloy, and copper are also available. Like T/Cs, RTDs are nonlin- ear, and must be compensated. RTD errors Self-heating not accounted for--An RTD Tips for must conduct a current in order to read tem- perature, and this current will heat up the sensor or RTD. The current through a Pt100 temperature testing RTD, for example, must be kept below 1mA to avoid problems with self-heating, and the current must be even smaller for nickel or nickel/iron alloy RTDs. Test lead compensation--The resistance Dale Cigoy, Keithley Instruments, Inc. of the test leads can have a great effect on the accuracy of an RTD temperature measure- E ment, and when leads are lon