Liquid-in-glass thermometers are used extensively as a means for accurate temperature measurement.
These instruments measure temperature when the liquid in the glass expands and contracts as temperature increases or decreases, the temperature measurement capability is therefore limited by the liquid used and normally has a maximum range of between -80 to 330 degrees.
To obtain the best possible data for Liquid in glass thermometer (LIG), RTD thermometer and PRT thermometer calibration we place the unit under test (UUT) thermometer along with our reference thermometer, then compare the reading of the test thermometer to our reference.
This method of thermometer calibration known as “the comparison method” has been the gold standard for Liquid in Glass (LIG) thermometers for decades because it is the most accurate and reliable method of thermometer calibration. We typically use the comparison method to calibrate thermometers.
ASTM Thermometers meet strict tolerances for specific applications. Each thermometer is supplied with a statement of compliance to E1 and E77 requirements. Thermometers are constructed of glass with permanent graduations and filled with mercury or non-toxic fluid.