Thermometers

Read our standard health & safety guidance

Refer to CLEAPSS Laboratory handbook, Section 10.7

Students must be shown how to use and read a thermometer with care.

A good, general-purpose thermometer has the following features:
• 300 mm long
• –10 to +110°C, with a scale in 1°C divisions
• liquid-in-glass, ‘spirit’ type with 76 mm immersion
• fitted with an anti-roll device (a triangular piece of plastic or rubber)
• with a reinforced bulb to allow for stirring

This is able to meet the requirements of virtually all investigations likely to be attempted. ‘Spirit-filled’ thermometers are generally satisfactory for introductory and intermediate work. Often, when measuring temperature differences, errors are cancelled out. However, when measuring precise temperatures, considerably above room temperature such as boiling water, mercury-filled thermometers give more accurate readings.

Shorter thermometers are also very useful since they are safer to use when, for example, heating liquids in a beaker. They are less likely to tip over. Short thermometers are also less likely to be snapped, and tend to be less expensive.

Health and safety checked, November 2007