When digital thermometers are used in the lab they should always be set to measure in Celsius degrees and the complete displayed temperature (including trailing zeroes) should be recorded.
- The plastic cover for the temperature probe may be left in place when measuring the temperature of water. For all other substances it should be removed to facilitate cleaning.
- Digital thermometers should not be left sitting in substances that are being heated. Temperatures should be taken by inserting the thermometer and maintaining a grip that keeps the probe from contacting the bottom of the vessel being heated.
- Always turn the thermometer off when done using it to preserve the batteries.
RHS swapped out mercury-in-glass thermometers for spirit (i.e., alcohol) thermometers several years ago for safety purposes. The ethanol in the thermometer is dyed red or blue to make it more visible.
To achieve the best results the thermometer must be immersed to a level based on the design of the thermometer.
- Partial-immersion thermometers must be immersed approximately 1/3 the length of the thermometer. A small mark on the back of the thermometer indicates the exact depth of immersion.
- Total-immersion thermometers must be immersed so that the entire length of the alcohol column is immersed. The thermometer may be lifted slightly (up to 1cm) to facilitate reading of the temperature.
- Do not use a thermometer as a stirring rod
- Never shake down a thermometer
- Use caution when inserting or removing a thermometer from a rubber stopper
- Make sure you have selected the appropriate measuring range for your thermometer—overheating can cause breakage