Meet the rigid requirements of ASTM designation E-1 which covers etched stem liquid in glass thermometers graduated in centigrade or Fahrenheit degrees which are specified in the methods of the American Society for Testing Materials. Each thermometer is filled above the liquid with an inert gas and is permanently in-scribed with the ASTM thermometer number, and serial number. Each thermometer is tested and standardized at the specified immersion in accordance with the standard method of testing etched stem liquid in glass thermometers, ASTM E-77
*Each Precision thermometer comes with a factory certificate of accuracy.