Manual Thermometers
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™ Lab Thermometer
A general purpose/stirring thermometer for a wide application of laboratory needs.
Fisherbrand™ Red Spirit Filled Total Immersion Thermometers
A general purpose/stirring thermometer for a wide application of laboratory needs. Fisherbrand™ Red Spirit Filled Total Immersion Thermometers have a white backing for readability.
Brannan™ Lab Thermometer
General purpose laboratory thermometer without calibration certificate.
Fisherbrand™ 10/30 Ground Joint Thermometers
Contains red organic liquid against white back glass.
Bohlender™ BOLA™ PTFE Thermometer for Flasks
Designed for use with BOLA flasks and a wide range of reachtion vessels. PTFE thermometers are suited for a variety of applications.
Quickfit™ Blue Spirit Thermometer with Integral Cone
Complies with ISO 386 standards. Quickfit™ Blue Spirit Thermometer with Integral Cone features an integral ground glass cone on the stem which allows direct fitting into Quickfit™ jointed apparatus. Filled with high visibility blue spirit.
H-B Instrument™ Durac™ Bi-Metallic Thermometers: 33mm Dial
With 2.5% or 2° accuracy—ideal for measuring temperatures in pipes, griddles and hot plates
Fisherbrand™ Red Spirit Filled Total Immersion Thermometers
A general purpose/stirring thermometer for a wide application of laboratory needs. Fisherbrand™ Red Spirit Filled Total Immersion Thermometers have a white backing for readability.
Brannan™ Dial Oven Thermometer with 3 Point Traceable Calibration Certificate
50 mm stainless steel dial oven thermometer with black temperature scales and red pointer. Complete with 3 point traceable calibration.
Amarell™ Standard Milk Glass Total Immersion Thermometer
Use for total immersion applications. The standard milk glass total immersion thermometers use non-mercury colored fill.
Brannan™ Precision Lab Thermometer with 3-points Traceable Calibration
High precision lab thermometer complete with calibration certificate.