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. Recalibration is performed as described in 6. 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. 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 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. 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.
In all cases only the current version of the standard as published by ASTM is to be considered the official document. Gentle tapping of the thermometer while held upright will cause the bubbles to rise to the surface. Your Alert Profile lists the documents that will be monitored.
However, these procedures may be applied to other liquid-in-glass thermometers.
The magnitude of any change in this reference reading as a result of the h heating period is a measure of the quality of the bulb glass and the adequacy of the previous heat treatment accorded the thermometer in manufacture. Add to Alert PDF.
ASTM E77 – 14e1
If any portion of the stem containing mercury is exposed, the emergent mercury column correction should be determined. 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.
They are simpler to use atsm a primary standard thermometer with its accessory equipment, the latter being capable of an order of precision and accuracy far in excess of that attainable with liquid-in-glass thermometers.
The choice of a secondary standard will be governed by various factors. Successive readings taken a. Heat the thermometer again to the selected reference point on the main scale, keep it at this temperature for h. Adjust the dividers to extend over 10 or 20 graduations, and successive intervals asgm be intercompared e777.
ASTM E77 – 14e1 Standard Test Method for Inspection and Verification of Thermometers
This keeps the viscosity of the liquid in the aztm low and aids in hastening drainage. In the case of ASTM thermometers, the diameter limits apply over the entire length of the section of the thermometer w77 tested. This is due to the effect of increased gas pressure above the column producing a distortion of the bulb.
E7 Subsctiption may be the perfect solution. A slight tapping of the 4 E 77 — 98 thermometer against the palm of the hand will facilitate this joining. Already Subscribed to this document. 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. Select clear pieces of ice or ice made from distilled or pure water.
The most common types of foreign matter which should be cause for rejection are glass chips, particles of w77 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.
Please first log in with a verified email before subscribing to alerts. 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.
Temperatures are not measured directly with this instrument.
ASTM E77 – 98 Standard Test Method for Inspection and Verification of Thermometers
Subscription pricing is determined by: This standard is also available to be included in Standards Subscriptions. Suitable types are described in Appendix X1.
It is only necessary to have a liquid-in-glass thermometer completely calibrated one time. It is frequently a good practice to immerse only the sstm of the thermometer. 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 ee77 purpose.
Temperatures may then be calculated using suitable resistance- temperature equations. The change in ice-point reading should then be applied to all readings.
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. Return the thermometer to the bath, preheated to the temperature of test, and heat for 24 h. Inspection for uniformity of spacing can generally be accomplished by eye, but for greater accuracy a pair of dividers may be used to advantage. If natural cooling is used, the correction should be determined within 1 h.
Thermometers that have a contraction chamber below the lowest graduation are likely to develop separations either in the chamber or above it. In some instances total-immersion thermometers may be used under conditions of complete immersion.