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ASTM E2995-15a(R2020) pdf free download

ASTM E2995-15a(R2020) pdf free download.Standard Specification for ASTM Thermohydrometers with Integral Low-Hazard Thermometers
1. Scope
1.1 This specification covers glass thermohydrometers of various scale graduation systems, intended for use in a variety of ASTM Test Methods. 1.2 The thermohydrometers presented in this standard are not exact replacements for the thermohydrometers in Specifi- cation E100; the thermometers have larger maximum permis- sible scale errors than do their Hg-filled counterparts. The user should decide if these thermohydrometers are appropriate for use in his or her application. 1.3 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 appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.4 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Terminology
3.1 Definitions: 3.1.1 The definitions given in Terminology E344 apply. 3.2 Definitions ofTerms Specific to This Standard: 3.2.1 ledger paper, n—a paper characterized by strength, high tearing resistance, eraseability, water resistance, ink receptivity, uniformity of surface, and smoothness. Discussion—Originally, ledger paper was used espe- cially for pen and ink records. Most ledger papers are surface sized, frequently subjected to appreciable wear, and must have a high degree of permanence and durability. 3.2.2 length ofthe scale, n—length of the nominal range in the stem, not including graduations extending above and below the nominal limits. 3.2.3 thermohydrometer, n—glass hydrometer having an integral thermometer. 3.2.4 top of the thermohydrometer, n—top of the finished instrument. 3.2.5 total length, n—overall length of the finished instru- ment.
4. Specifications
4.1 Thermohydrometers shall conform to the detailed speci- fications in Table 1 and to the general requirements specified in Sections 5 – 15. 4.2 Thermohydrometers shall conform to the inspection criteria found in Section 16 and the calibration and verification criteria found in Section 14. 4.3 Thermohydrometers manufactured to previous revisions of this specification shall retain the same ASTM status as those meeting current specifications. 4.4 At time of purchase, scale errors shall not exceed the maximum permissible scale error found in Table 1. N OTE 1—Caution—Users should be aware that both temperature and density indications of thermohydrometers may change with rough handling, shock, exposure to aggressive liquids, and thermal cycling, among other factors. Consequently, test results and performance obtained at the time of manufacture may not necessarily apply throughout an extended period of use. Periodic calibration or verification of these instruments, in accordance with procedures set forth in Standard Test Method E126 (for the hydrometer), or Standard Test Method E77 (for the integral thermometer), is recommended.
5. Type
5.1 Thermohydrometers shall be of the constant mass, variable displacement type. Thermohydrometers shall be made of glass, except for the scale, ballast, cement, and the thermo- metric liquid of the thermometer. 5.2 The outer surface of the stem and body shall be symmetrical about the vertical axis. There shall be no uneven or unnecessary thickening of the walls, and no abrupt changes or constrictions that would hinder thorough cleaning or tend to trap air bubbles when the instrument is immersed. 5.3 The thermohydrometer shall float with its axis vertical in the liquids for which it is intended. 5.4 The thermohydrometer shall be thoroughly dry on the inside when sealed. The top ofthe stem shall be neatly rounded without unnecessary thickening. 5.5 The glass shall be smooth, transparent, and free of bubbles, strain patterns, cracks, or other imperfections that might interfere with the use of the thermohydrometer. The glass shall adequately resist the reaction of chemical agents to which thermohydrometers may be exposed, and also shall have suitable thermal properties to permit its use over the range of temperatures to which it may be subjected. In general, glasses suitable for constructing the bulbs of thermometers are satis- factory for thermohydrometers. 5.6 These thermohydrometers shall be fabricated from soda- lime glass tubing having a thermal cubical expansion coeffi- cient of (25 6 2) × 10 -6 per ºC. N OTE 2—The value of the thermal cubical expansion coefficient given above is consistent with the conventional value given in ISO 1768.

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