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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A slight tapping of the 4 E 77 — 98 thermometer against the palm of the hand will facilitate this joining. Discontinuities in the spacing are evidence of faulty graduating. Suitable types are described in Appendix X1. Inspect the thermometer for differences in appearance of the tested and untested sections of the scale portion.
ASTM E77 – 14e1 Standard Test Method for Inspection and Verification of Thermometers
If any portion of the stem containing mercury is exposed, the emergent mercury column correction should be determined. 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.
Strains in the glass as observed with a polarized asrm strain gage near enlargements in the stem or bore, or at the top of the thermometer, are detrimental.
No method has been discovered that will entirely prevent such displacement of the gas. Allow the thermometer to cool, at the same rate as at the start of the test, to the temperature referred to above, and redetermine the reference reading under the same conditions as before.
In all cases only the current version of the standard as published by ASTM is to be considered the official document. For fractionally graduated thermometers a calibrated set of the following thermometers is recommended.
ASTM E77 – 14e1 – Standard Test Method for Inspection and Verification of Thermometers
Return the thermometer to the bath, preheated to the temperature of test, and heat for 24 h. 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.
Adjust the dividers to extend over 10 or 20 graduations, and successive intervals can be intercompared rapidly. Ice points should be taken every 3 months.
For more stubborn separations it may be necessary to cool the bulb in dry ice to a point low aatm to bring all of the liquid into the bulb itself. Need more than one copy? Standards Subscriptions from ANSI provides a money-saving, multi-user solution for accessing standards.
This standard is also available to be included in Standards Subscriptions. When the column itself follows into the chamber, ee77 separated portion usually will join onto the main column. Proceed to Checkout Continue Shopping. This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version.
Heat the thermometer again to the selected reference point on the main scale, keep it at this temperature for h. Allow the thermometer to cool as described in and then repeat the procedures described in and. The bulb should be allowed to warm up slowly. This keeps the viscosity of the liquid in the capillary low and aids in hastening drainage.
As the ice melts it will be necessary to drain off some of the water and add more crushed ice. Allow to cool slowly. Thermometers that have a contraction chamber below the lowest graduation are likely to develop separations either in the chamber or above it.
Inspection for uniformity of spacing can generally be accomplished by eye, but for greater accuracy a pair of dividers may be used to advantage. More complete information on the construction and use of primary standard thermometers may be obtained from NIST SP In reading thermometers, account must be taken of the fact that the lines are of appreciable width.
ASTM E77 – 14e1
It is frequently a good practice to immerse only the bulb of the thermometer. Gentle tapping of the thermometer while held upright will cause the bubbles to rise to the surface. Last previous edition approved in as E 77 —