Atkins Thermocoupler
A thermocouple is a coupling of two dissimilar alloy wires, which can be welded into the tip of a probe shaft, or set in a thermally conductive potting. A thermocouple meter/instrument purchased along with several different types of thermocouple probes may be used to measure all kinds of temperature from internal food to equipment surfaces.
They are very accurate, offer a wide temperature range, and are extremely durable. The response time is a function of the placement of the junction in the tip of the shaft, the thermal conductivity of the potting used and the diameter of the probe shaft.