Calibrating a current temp input

[Tonk]

I am trying to calibrate an Siemens 13 bit analogue card to read a temperature can anybody help me on how to set the current input to be linear with respect to my temperature applied. Have tried several ways in my PLC but having no luck so far. Can track my temperature about 1/3 of my scale then my displayed temp to my actual measured temp using a fluke start to deviate.

 

[TConnolly]

I assume by the title that the analog input is a current input (ie 4-20mA). Is that correct?

If so, then what are you using as the temperature sensing element? Is it a thermocouple, RTD, thermistor, or other device?

If you are using a thermocouple connected through a tc to current converter, does the converter provide thermocouple linearization? Many converters do not linearize; the linearization must be done in the PLC. This can be a complex and CPU intensive operation - but it is something that I do from time to time.