This specification covers liquid-in-glass ASTM thermometers using low hazard thermometric liquids. The gas filling above the liquid shall be nitrogen or other suitable inert gas. The filling gas shall be chosen to have very low solubility in the thermometric fluid. The stem shall be made of suitable thermometer tubing and shall have a plain front and enamel back. The bulb shall be made of glass and the following distances between graduations and the bulb, and between graduations and enlargements in the capillary, are minimum limits acceptable. All graduation lines, figures, and letters shall be clearly defined, suitably colored, and permanent. The width and the sharpness of the graduation lines shall be designed in accordance with necessary space between the graduations and the desired accuracy of interpolation. The middle of the graduation line shall be accurately determinable. In addition, the graduation lines shall be straight, of uniform width, and perpendicular to the axis of the thermometer. On partial immersion thermometers an immersion line shall be permanently marked on the front of the thermometer at the distance above the bottom of the bulb as specified. The immersion inscription shall be written in capital letters and abbreviated. The terminal number shall be in full when there are one or more numbered graduations between it and the next full number. The special inscription specified shall be marked on the thermometer in capital letters and Arabic numbers without the use of periods.

1.1 The purpose of this standard is to specify liquid-in-glass ASTM thermometers using low hazard thermometric liquids defined in this standard.

1.2 This standard specifies liquid-in-glass thermometers graduated in degrees Celsius or degrees Fahrenheit that are frequently identified and used in methods under the jurisdiction of the various technical committees within ASTM. The current approved thermometers are listed in Table 1.

1.3 The technical requirements for the thermometric liquids used in the thermometers in Table 1 are specified in Annex A1. Tests for conformity to the technical requirements are also found in Annex A1.

Note 1—It has been found by experience that ASTM Thermometers, although developed in general for specific tests, may also be found suitable for other applications, thus precluding the need for new thermometer specifications differing in only minor features. However, it is suggested that technical committees contact E20.05 before choosing a currently designated thermometer for a new method to be sure the thermometer will be suitable for the intended application.

1.4 For full rationale, see Appendix X1.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.