If you work with high-temperature thermocouples and youd rather test them than throw them out, but you haven't found a calibration instrument that checks them economically, now you have a solution. This calibrator delivers all the benefits to make verifying your thermocouples productive and effective. Insert A (variety block) 1/2, 3/8, 1/4, 3/16, 1/8, and 1/16 holes.