An Overview of Oven Thermometers
There are two main types of oven thermometer.
Pre-installed oven thermometers, as the name suggests are built into an oven and, in most cases have a temperature display on the outside control surface of the oven.
A stand-alone oven thermometer is bought separately and placed in the oven. These standalone devices come in many different shapes and sizes. Take a look a sample of suitable Comark thermometers here.
Oven thermometers work on what is known as “point principle” They take a reading from a particular part of the oven. They are positioned and calibrated to give an accurate reading of the cooking temperature of the oven.
This is an important distinction. The heating element, oven walls and oven door might all have slightly different temperatures that vary up and down from the cooking temperature. Therefore, the positioning and calibration of an oven thermometer is important to ensure it reflects the mean cooking temperature rather than one of these outlying temperatures.
The oven thermometer should, of course be visible through the oven door without need to open it. For ovens with opaque doors then you will need to use a thermometer with an oven proof external probe.
Placing an Oven Thermometer
Most food is best positioned for cooking in the centre of an oven. Therefore, to get the most accurate reading, an oven thermometer should be placed on the middle shelf. There will be hooks or bracing bars above or below the oven thermometer allowing it to be either hung from shelf or cantilevered to sit on top of a shelf.
Calibrating an Oven Thermometer
For your own peace of mind, and to ensure the thermometer is correctly positioned it can be calibrated and checked prior to first use. To do so, follow these simple steps
Place the oven thermometer in the correct position in the oven as described above or in the thermometer’s instruction guide.
Set the oven to 350°F and allow the oven to pre-heat for 20 minutes.
Without opening the door, take a temperature reading
Over the next hour take 3 more readings, one every 20 minutes.
If the thermometer and oven are working correctly the readings should fall in a range between 320°F to 374°F with the average temperature of all four readings no more than 20°F from 350°F.
A deviation from this may indicate a problem with your oven and it should be checked by a qualified service engineer.