Manual Thermometers
Mercury, non-mercury (liquid in glass), or bimetallic thermometers with analog displays, for general and application-specific use, with various temperature-range capacities and accuracies; may be traceable or certified to international standards.
In 1714, the mercury-in-glass thermometer was invented in Europe by physicist Daniel Gabriel Fahrenheit. Typically, the mercury is contained in a reservoir that opens to narrow glass tube. The distance that the mercury flows into the tube is dependent on the temperature to which the thermometer is subjected. The space above the mercury may be filled with air or an inert gas, or it may be a partial vacuum.
Thermometers are calibrated by exposing them to a known temperature and then marking the height of the mercury at that temperature. For example, one might calibrate to the freezing temperature of water (0°C or 32°F) by placing the thermometer in a mixture of ice and water. Then the thermometer could be submerged in boiling water to determine the point where the water changes from a liquid to a vapor (100°C or 212°F).
Mercury thermometers are still considered to be some of the most accurate temperature indicators. They can be used for a wide range of temperatures, from -37°C to 356°C (-35°F to 673°F). Modifications such as adding an inert gas above the mercury or replacing the glass with fused quartz can extend the upper temperature limit to as high as 800°C (1,470°F).
Mercury cannot be used below -38.83°C (-37.89°F), the temperature at which it becomes a solid. Moreover, nitrogen in the thermometer can flow down into the column and become trapped if the mercury solidifies, which makes the thermometer unusable. Use a thermometer that contains a mercury-thallium alloy for measuring lower meteorological temperatures – it will remain liquid to -61.1°C (-78.0°F).
Fisherbrand™ Max-Min Thermometer - Dual Scale
Waterproof U shaped thermometer.
Fisherbrand™ Durac™ General Purpose Liquid-in-Glass Partial Immersion Thermometer, Economical Grade
Red organic liquid with white back glass.
Safety Red-Spirit™ Thermometers
Solid-stem glass thermometers with dark scale and white background are easy for students to read and can withstand heavy usage.
H-B Instrument™ Easy-Read™ Environmentally Friendly Liquid-In-Glass Tank Thermometers
Cup holds liquid sample for effortless reading.
H-B Instrument™ Durac™ Incubator Thermometers
Designed with a swell in the stem to hold the thermometer in place.
Science First Soil Thermometer, 32cm
Take the guesswork out of planting
Aqua Phoenix™ Micro Thermometers
Perfect for use with microscale setups.
Wilmad Labglass THERM NON-MERC 10/30 -10/+250C
Thermometer, Celsius, Non-Mercury, with [ST] 10/30 Inner Joint. Temperature Range: -10degree to + 250degreeC; Length Below Joint: 280mm. Made with mineral spirits filling in white glass. With 1degreeC subdivisions.
Med Vet International Temporalscanner Temporal Contact Thermometer, Temporal Probe Handheld, 124275, Each
Fast, safe, and comfortable for the user Disposable cover use optional Industrial-duty construction
