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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ASTM E77 – 14e1
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.
Any stones or striae that distort the bore or its appearance should be cause for rejection. In reading thermometers, account must be taken of the fact that the lines are of appreciable width. Thermometers that have a contraction chamber below the lowest graduation are likely to develop separations either in the chamber or above it. Please first log in with a verified email before subscribing to alerts. Mercury, or its vapor, may be hazardous to health and atm to materials.
In the case of ASTM thermometers, the diameter limits apply over the entire length of the section of the thermometer being tested. Burning out, loosening, chalking, or fading of the pigment shall be cause for rejection. 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. In all astk only the current version of the standard as published by ASTM is to be considered the official document.
Return the thermometer to the bath, preheated to the temperature of test, and heat for 24 h. More complete information on the construction and use of primary standard thermometers may be obtained from NIST SP You can download and open this file to your own computer but DRM prevents opening this file on another computer, including a networked server.
This keeps the viscosity of the liquid in the capillary low and aids in hastening drainage. The bulb should be allowed to warm up slowly. Inspection for asm of spacing can generally be accomplished by eye, but for greater accuracy a pair of dividers may be used to advantage.
As the voice of the U. By softly tapping on f77 soft spongy material or against the hand it usually is possible to bring the liquid together in the bulb. They should be completely recalibrated every 6 to 12 months, depending upon the temperatures of usage. 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.
It is frequently a good practice to immerse only the bulb of the thermometer.
Recalibration is performed as described in 6. 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.
ASTM E77 – 14e1 – Standard Test Method for Inspection and Verification of Thermometers
Strains in the glass as observed with a polarized light strain gage near sstm in the stem or bore, or at the top of the thermometer, are detrimental. Adjust the dividers to extend over 10 or 20 graduations, and successive intervals can be intercompared rapidly. Astn 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.
These thermometers can be used as standards to calibrate other thermometers similar in all details of construction above the immersion point, but may differ ashm the immersion point to the extent of including an auxiliary ice point scale. A slight tapping of the 4 E 77 — 98 thermometer against the palm of the hand will facilitate this joining.
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. Gentle tapping of the thermometer while held xstm will cause the bubbles to rise to the surface.
Originally published as E 77 — 49 T.
Caution should be taken when handling mercury and mercury containing products. 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.
Inspect the thermometer for differences in appearance of the tested and untested sections of the scale portion.
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. If bubbles are observed in the bulb, they can generally be removed by cooling the bulb with dry ice or other convenient coolant until all the liquid is drawn into the bulb.
Successive readings taken a. Secondary standards may be of the following types. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. In some instances total-immersion thermometers may be used under conditions of complete immersion. 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.
This standard has been approved for use by agencies of the Department of Defense. It is only necessary to have a liquid-in-glass thermometer completely calibrated one time. 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.
This is due to the effect of increased gas pressure above the column producing a distortion of the bulb. 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.
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