An HVAC technician must measure water temperatures, as well as dry bulb and wet bulb temperatures of air. For example, you may have to measure the entering and leaving temperatures for a coil - both for air and for water. Accurate temperature readings can be critical. An error of even 1 degree F can make a substantial difference when measuring temperatures and adjusting the water flow to a chilled water coil.
To measure temperature and humidity properly, the technician must be able to use all of the following instruments: