A light weight (only 3 oz.), all-aluminum head for single or duplex thermocouple elements. Readily adapted to small diameter protection wells or mineral oxide insulated sheathed thermocouples up to .250 diameter by use of a 1/8″ NPT compression fitting. Also available with a 1/4″ and 3/8″ NPT female thread for large sheath and well diameters. Head can be subjected to a maximum operating temperature of 250°F (121°C). Series 1020D is the standard dust cover head containing neoprene grommet around conductor outlet to prevent mechanical abrasion of the insulation. A neoprene O-ring seals the threaded cover on all models. Series 1020W is the waterproof version of the screw cover head having a neoprene grommet at the outlet and capable of scaling leadwires from 24 gauge to 16 gauge. This cover will moisture proof the terminal head under the most adverse conditions.