Review on REOTEMP S2 F1 Clamp Surface Thermometer by Mark Taylor

This is an inexpensive analog thermometer that attaches to a water pipe. Inlet and outlet pipes of a water heater. The one at the entrance is mainly for curiosity. I often look at the one on the exhaust pipe to compare heater settings and monitor performance. There was nothing to indicate accuracy, so my working guess is +/- one division (5°F) of the displayed value. One day I pull out my DMM and Type-K thermocouple and take some measurements. But I don't expect much of a difference due to the combined measurement error of the meter and thermocouple. (I'm retired, so I don't have the resources of my former calibration lab.)