How do I check that my probe thermometer is still performing within specification?

The simplest and most effective way of checking the accuracy is to make an ice slurry. A procedure for doing this is detailed below:

1. Obtain a coffee mug or small container and quarter fill it with crushed ice
2. Add water and fill the mug until it is half full.
3. Allow the mix to sit for 2 minutes & stir for 10 seconds. Your ice slurry is now prepared.
4. From here place the probe of your thermometer to be tested into the ice slurry & slowly stir & wait for the temperature reading on the display to stabilise.
5. The temperature displayed should be 0ºC +/-1ºC (taking into account the written manufacturer’s specification for the unit).
6. If the temperature is within -1ºC to +1ºC as per the manufacturer’s specifications, then the thermometer is still within specification and can be returned to service.
7. If the thermometer displays greater than -1ºC to +1ºC the unit should be repaired, re-calibrated or replaced

It is worth noting this information should be recorded so that you have a written record of when this check was performed. Please record the following information when you perform this check (time, date, reading attained & who completed the check) as this will keep a running record of how the thermometer has performed over time. An example of how the check should be recorded is shown below: