Greisinger standard immersion measuring probe type k greisinger gtf 400 the greisinger gtf 400 is an immersion probe that will allow you to measure temperature levels of liquids and gases between the range of 65degc to 550degc the probe has been designed to work with thermocouple thermometers with type k inputs it has a 1m silicone cable terminated with a mini thermocouple din plug greisinger gtf 400 type k immersion probe