While checking if a gas or a halogen stove could be used for sous vide cooking at low and constant temperature we used the Mastrad digital thermometer. I didn’t purchase Mastrad external probe to determine the core temperature of a product but to verify the temperature of the water contained in the pan only. For this specific purpose Mastrad probe was perfect except that I learned to one’s cost that Mastrad’s probe is not waterproof! I didn’t know that you should not immerge the probe above a specific point indicated on the picture below.
Then my thermometer became crazy and indicated a temperature 30°C higher than real. This dysfunction remained until I put the probe (including the metal cable) to soak in demineralized water for 30 minutes and dried the probe in the oven. Mastrad probe works perfectly again.
In order to complete my basic equipment for sous vide cooking at low and constant temperature I had to find a digital thermometer with an external probe. Here is my choice: a Mastrad thermometer that I purchased EUR 29 on internet. I was amazed to see how reactive the sensor was. You just have to put it in the water and you can see the temperature moving on the spot and reaching the correct temperature in 1 or 2 seconds. This precision will be necessary when measuring the temperature variation with the different techniques of sous vide cooking.