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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Last previous edition approved in as E 77 — Burning out, loosening, chalking, or fading of the pigment shall be cause for rejection.
asrm Add to Alert PDF. 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 e7 this point. If the document is revised or amended, you will be notified by email.
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. Under these conditions oxidation of the mercury will occur and will normally be evidenced by the production of crystals of red oxide of mercury after 10 to 12 h of exposure.
Thermometers that have a contraction chamber below the lowest graduation are likely to develop separations either in the chamber or above it. If any portion of the stem containing mercury is exposed, the emergent mercury column correction should be determined.
Ice points should be taken every 3 months. Inspection for uniformity of spacing can generally be accomplished by eye, but for greater accuracy a pair ast, dividers may be used asttm advantage. They should be completely recalibrated every 6 to 12 months, depending upon the temperatures of usage.
ASTM E77 – 14e1 – Standard Test Method for Inspection and Verification of Thermometers
asgm Recalibration is performed as described in 6. Organic liquids as used in thermometers, in contrast to mercury, wet the glass. For more stubborn separations it may be necessary to cool the bulb in dry ice to a point low enough to bring all of the liquid into the bulb itself.
Discard any cloudy or unsound portions. By softly tapping on a soft spongy material or against the hand it usually is possible to bring the liquid together in the bulb. Temperatures may then be calculated using suitable resistance- temperature equations. Secondary standards may be of the following types. Your Alert Profile lists the documents that will be monitored. In order that it shall be satisfactory for such use, the thermometer should meet the requirement that the ratio of resistances at the steam and ice points shall be greater than 1.
As the voice of the U. This standard is not included in any packages. Originally published as E 77 — 49 T. 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.
If a small portion of the liquid has separated at the top of the column and the thermometer is provided with an expansion chamber, the liquid usually can be joined by carefully and slowly heating the bulb until the separated portion is driven into the expansion chamber. Heat the thermometer again to the selected reference point on the main scale, keep it at this temperature for h. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
These thermometers can be used as standards to calibrate other thermometers similar in all details of construction above the immersion point, but may differ below the immersion point to the extent of including an auxiliary ice point scale. The choice of a secondary standard will be governed by various factors.
If natural cooling is used, the correction should be determined within 1 h. If a mercury separation is observed in the stem, several different ways are suggested for joining the columns, depending on the construction of the thermometer and the type of separation.
Successive readings taken a. In reading thermometers, account must be taken of the fact that the lines are of appreciable width.
Return the thermometer to the bath, preheated to the temperature of test, and heat for 24 h. For fractionally graduated thermometers a calibrated set of the following thermometers is recommended. The most common types of foreign matter which should be cause for rejection are glass chips, particles of dirt or lint, oxide of mercury either red, yellow, or blackproducts of glass weathering commonly called white deposit, and stones or iron spots traceable to faulty glass fabrication.
You can download and open this file to your own computer but DRM prevents opening this file on another computer, including a networked server. 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.
This is due to the effect of increased gas pressure above the column producing a distortion of the bulb.
If such globules appear to unite and then reappear on cooling the bulb, they are indicative of oxidation of the mercury or the xstm of obstructions in the bore, and should result in rejection of the thermometer. More complete information on the construction and use of primary standard thermometers may be obtained from NIST SP Such thermometers should always be inspected for these separations, which can be repaired by the procedures aetm above.
ASTM E77 – 14e1
If natural cooling in still air is used, determine the reference reading within 1 h. Already Subscribed to this document. No method has been discovered that will entirely prevent such displacement of the gas. A superscript epsilon indicates an editorial change since ast last revision or reapproval. Its electrical resistance is determined by comparison with a standard astn, using a potentiometer, a Kelvin-type double bridge, or a Wheatstone bridge, preferably of the Mueller type or an AC resistance bridge.
This standard has been approved for use by agencies of the Department of Defense. Allow to cool slowly. Inspect the thermometer for differences in appearance of the tested and untested sections of the scale portion. We have no amendments or corrections for this standard. If the pigment in the scale etchings washes out or fades, the thermometer will be difficult to read. A number in parentheses e7 the year of last reapproval.