E77 – 98 Standard Test Method for Inspection and Verification of Thermometers, Calibration-temperature instrumentation, Liquid-in-glass thermometers. Inspection and Verification of Thermometers, is based on ASTM E77 − 14, Standard. Test Method . E1 Specification for ASTM Liquid-in-Glass Thermometers. Buy ASTM E() Standard Test Method for Inspection and Verification of Thermometers from SAI Global.
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Please first verify your email before subscribing to alerts. Scale corrections should always be applied in the use of these standards.
The thickness of such qstm should approximate the diameters of the holes to minimize errors resulting from the axis of the thermometer stem being other than normal to the xstm of the gage. As the ice melts it will be necessary to drain off some of the water and add more crushed ice. In the case of diameter measurements, the bulb or other portions of the thermometer being tested should not enter the smaller of the holes in the ring gage see 5. No method has been discovered that 7e7 entirely prevent such displacement of the gas.
It is frequently possible to join such separations by cooling the thermometer so that the separated portion as well as the main column both stand in the chamber.
It is only necessary to have a liquid-in-glass thermometer completely calibrated one time. If natural cooling is used, the correction should be determined within 1 h. Any stones or striae that distort the bore or its appearance should be cause for rejection. Normally, the effect of taper in the capillary or nonlinearity in the expansion characteristics of organic liquids is manifested by a gradual change in the spacing of the graduations.
Discard any cloudy or unsound portions. Select clear pieces of ice or ice made from distilled or pure water. Mercury, or its vapor, may be hazardous to health and corrosive to materials. If such globules appear to unite and then reappear on cooling the bulb, they are indicative of oxidation of the mercury or the presence of obstructions in the bore, and should result in rejection of the thermometer. Organic liquids as used in thermometers, in contrast to mercury, wet the glass.
Metal block baths and the salt and tin comparator baths, described in Appendix X1, are examples of the type of equipment that has been found to be suitable for this purpose. Total-Immersion Thermometers—In the case of general purpose total-immersion thermometers, the sensitivity of the thermometers to be tested will govern the choice of standard.
ASTM E77 – 14e1
Current edition approved Nov. Inspection for uniformity of spacing can generally be accomplished by eye, but for greater accuracy a pair of dividers may be used to advantage. Successive readings taken a. If any portion of the aatm containing mercury is exposed, the emergent mercury column correction should be determined. Burning out, loosening, chalking, or fading of the pigment shall be cause for rejection. It must be emphasized that to obtain meaningful results, the procedure adopted after the h period of heating must be identical to that used in the original calibration.
Rinse the ice with distilled water and shave or crush into small pieces, avoiding direct contact with the hands or any chemically unclean objects.
Standards Subscriptions from ANSI provides a money-saving, multi-user solution for accessing standards. Suitable types are described in Appendix X1.
Allow the thermometer to cool as described in and then repeat the procedures described in and. In all cases only the current version of the standard as published by ASTM is to be considered the official document. You may delete a document from your Alert Profile at any time. For fractionally graduated thermometers a calibrated set of the following thermometers is recommended.
Your Alert Profile lists the documents that will be monitored. By softly tapping on a soft spongy material or against the hand it usually is possible to bring the liquid together in the bulb. The bulb should be allowed ee77 warm up slowly. A slight tapping of the 4 E 77 — 98 thermometer against the palm of the hand will facilitate this joining.
ASTM E77 – 14e1 Standard Test Method for Inspection and Verification of Thermometers
Inspect the thermometer for differences in appearance of the tested and untested sections of the scale portion. Such thermometers should always be inspected for these separations, which can be repaired by the procedures described above.
Heat the thermometer to the selected reference point on the main scale, maintain the temperature for at least 15 min, and determine the scale correction at this point.