The Tel-Tru MT39R is a dial thermometer intended for food temp measurement. It can be left in the oven while cooking, and is sealed against moisture entry. However, the manufacturer advises against submerging or putting it in the dishwasher.
It was accurate throughout its range and had a large dial with 2º markings. There is only a Fahrenheit scale, no Celsius. The thermometer can be adjusted by turning a nut on the rear of the unit, but it was accurately calibrated from the factory. We checked a couple of extra temperatures to gauge the accuracy of the unit. As you can see, it was very close, being only two degrees high at every temperature we tested:
100ºF actual reading 102º
160ºF actual reading 162º
The manufacturer’s contact info, including address, telephone number, e-mail and website, is found on the instruction sheet. There is no explicitly stated warranty.
While we lean toward digital units, this bi-metallic dial thermometer exceeded accuracy expectations. The dial is easy to read, and it should be a reliable unit. We give it a Silver medal for its accuracy, construction and simplicity.
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Bill McGrath - Bill McGrath is AmazingRibs.com's Thermometer Maven. He has sophisticated equipment, an electrical engineering degree from Cornell University, and an MBA (almost) from UC Berkeley. Despite being mostly retired, he is still the person responsible for developing and updating all of ExxonMobil's training modules.