This specification is applicable to glass thermohydrometers of various scale graduation systems, intended for use in a variety of ASTM Test Methods. The thermohydrometers covered by this specification have larger maximum permissible scale errors than do their Hg-filled counterparts. It is up to the user to decide if these thermohydrometers are appropriate for use in his or her application. This specification establishes requirements for thermohydrometers with respect to type, body, ballast, stem, scale, markings, calibration and verification, packaging, and inspection procedures.