Review on 🌡️ Digital 2 Channel K-Type Thermometer with 4 Thermocouples: High Temperature Kelvin Scale Dual Measurement Meter Sensor - Handheld Desktop, Wired & Stainless Steel,-50~1300°C (-58~2372°F) by Srinivas Johnson

I used this to measure the temperature of the air conditioning line at the inlet and outlet of the evaporator to measure superheat. The connectors must be inserted in the correct direction or you will get bad readings. There are no markings on the plugs. Once you determine the correct orientation, both thermocouples will be within 2 tenths of a degree of each other. (0.2'F) I haven't measured accuracy against a standard, just relative to each other. I taped the ends of the tubes to get good contact and then insulated them. Did the same but used tape when measuring the oil pan temp. . You just have to be very careful when you pull on the tape to avoid damaging the soldered end. You can't complain about the price.