Home>ASTM Standards>ASTM E542-01(R2021) pdf free download

ASTM E542-01(R2021) pdf free download

ASTM E542-01(R2021) pdf free download.Standard Practice for Calibration of Laboratory Volumetric Apparatus
1. Scope
1.1 This practice covers procedures for use in the calibration of volumetric ware, in accordance with Specification E694 such as is in common use in chemical and clinical laboratories. It is based on the gravimetric determination of the quantity of water either contained or delivered, and the conversion of this value to true volume at the standard temperature of 20 °C by means of suitable equations and standard tables. Calibration using mercury is excluded. Calibration may be performed using alternative gravimetric methodology, provided that it is demonstrated and documented that the results obtained are equivalent to those obtained using the methodology described herein. 1.2 This practice is intended to encompass capacity ware between the limits of 0.1 cm 3 and 2000 cm 3 . Typical products falling within the purview of this practice are burets graduated “to deliver”, graduated cylinders, volumetric flasks, specific gravity flasks, measuring and dilution pipets, and transfer and capacity pipets. 1.3 The procedures are not recommended for calibration of apparatus with capacities below 0.1 cm 3 , such as microglass- ware. 1.4 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. 1.5 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.
4. Significance and Use
4.1 The primary purpose of this practice is to provide uniform procedures that may be used to accurately calibrate a wide variety of volumetric ware. The techniques are simple in concept and can provide reliable results, provided the proce- dures are followed faithfully. Accordingly, the practice should provide a means for checking the original calibration of glassware and similar apparatus and for periodic rechecks as the need should arise. 4.2 Borosilicate volumetric glassware will hold its calibra- tion indefinitely provided that it is not exposed to hydrofluoric acid, hot phosphoric acid, or strong, hot alkalis, and that it is not heated above 150 °C when dry. A frosting of the glass surface (viewed when dry) indicates that chemical attack has occured, and recalibration may be in order. As a precaution, however, it is recommended that the glassware be recalibrated after ten years of service regardless of its appearance. 4.3 Soda-lime volumetric glassware will become frosted with time because ofattack from moisture in the atmosphere as well as from the chemicals mentioned above. In addition, it should not be heated above 90 °C when dry. It is recommended, therefore, that it be recalibrated after five years of service unless frosting (viewed when dry) is observed sooner.
5. Units of Measurement
5.1 Capacity—The basic SI unit for volume is the cubic metre, m 3 . Due to its large size, it is rarely used in volumetric calibration. Rather, the cubic centimetre, cm 3 , is used and will be employed in this practice. The unit, millilitre, mL, may be considered as equivalent to the cubic centimetre. 5.2 Standard Temperature—Volumetric ware is almost uni- versally calibrated at 20 °C. The procedures described provide for such a calibration. When it is necessary to work at higher ambient temperatures, such as is the case in tropical countries, calibration may be required at the International Standards Organization (ISO) recommended temperature of 27 °C. Equa- tions are given to correct the calibrated volume to other temperatures as this may be required or desired.

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