There is a thing called a thermocouple simulator (probably available in a RTD version as well), that allows you to dial in a temperature you want to simulate, and it gives the appropriate output to test your monitoring/control system. If you can find one of these with a potentiometer for setting, you should be able to modify it for ma input, depending on how elegant you need to be. You might also consider a DC-DC signal conditioner with the output set for millivolts. This might be close enough. With RTD inputs, this solution might be a problem, because the instrument is trying to drive current through the
sensor, where a tc is actually producing the voltage independently.
Advanced Control Technologies Inc ( "www.act-solutions.com":http://www.act-solutions.com ) model DRN3.1 provides analogue input to proportional resistance output which may be close to what you want.
We use PLC for testing our very complex control solutions and the test PLC can only generate 0-20 mA signals since there is nothing like RTD or T/C output.
