When a customer needs to measure the temperature and relative humidity in a high temperature/high humidity environment, such as a humidity chamber or jerky cooking, they can either spend a great deal of money on specialized probes and meters, or they can measure the wet bulb and dry bulb temperatures and calculate the relative humidity.
The term "wet bulb" refers to covering the temperature sensor with a wet wick/sock. The sensor being covered can be a mercury bulb on the end the the thermometer, or a thermocouple or thermister at the end of a probe. The other end of the wick/sock should be placed in a vessel containing water, so that the wick does not dry out during the test. However, in high humidity environments (90%+), this is not typically a problem, so the vessel does not have to be very large.
Tech Instrumentation has had great success in assisting customers to measure relative humidity in high temperature and humidity environments using the following instruments:
This system also allows a third probe that can be used for internal meat temperature or another temperature reading of your choice.