How to identify whether temperature sensor is RTD or Thermocouple?
RTD has two,three or four leads per sensing element Thermocouple has two leads per junction RTD typically have red,white,green or black leads TC color match thermocouple type- red(common),yellow,purple,blue,white.
RTD will have about 109 ohms between leads at 20 deg C Thermocouple lead resistance is typically less than 1 ohm
TC grounded junction has path from leads to case
RTD leads are not magnetic TC type J has one iron lead which is highly magnetic