These tough thermometers from Cole-Parmer Instrument Co. of Vernon Hills, Ill., are ready to take your demanding temperatures. Simply insert the included bead thermocouple probe to take readings instantly. Fluke 50S and 50D thermometers (91500-series) are ideal for simple temperature applications-use to take readings, hold readings, scan readings, measure differential temperature and to determine minimum/maximum recording. Measure temperature with type J and K thermocouple probes.