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ASTM E319-85(2008)
Standard Practice for the Evaluation of Single-Pan Mechanical Balances
9 стр.
Заменен
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Разработчик:
Зарубежные/ASTM
Сборник (ASTM):
14.04 Laboratory Apparatus; Degradation of Materials; SI; Oxygen Fire Safety / Лабораторная аппаратура; Деградация материалов; Международная система единиц СИ; Кислород и пожарная безопасность
Тематика:
Laboratory Testing
Описание
Значение и использование

Monitoring Weighing PerformanceThis practice provides results in the form of control charts which measure the weighing capability at the time of the test. A series of tests at appropriate intervals will monitor balance performance over a period of time. A marked change from expected performance may result from a variety of causes including: maladjustment, damage, dirt, foreign material, and thermal disturbances. If the test results are to indicate future performance, any disturbances that occur exterior to the balance must be brought under control (2).

Acceptance TestsThis practice may also be used as acceptance tests for new balances. For this purpose, the tests should be conducted under favorable, but not necessarily ideal, conditions. Since systematic error in the course of the zero and the course of the sensitivity may be caused by disturbances external to the balance, limits on these errors are not ordinarily prescribed in acceptance requirements.

Область применения

1.1 This practice covers testing procedures for evaluating the performance of single-arm balances required by ASTM standards.

1.2 This practice is intended for but not limited to sensitivity ratios of 106 or better and on-scale ranges of 1000xd or more where d = reability either directly or by estimation.

1.3 This practice can also be applied to other single-pan balances with mechanical weight changing of different capacities or sensitivities with appropriate test loads and calibration weights.

Note 1—Mechanical balances of this type have largely been replaced by automatic electronic balances incorporating a variety of operational principles. Nevertheless, some single-pan mechanical balances are still manufactured and many older balances will remain in service for years to come. One type of automatic electronic balance, the so-called hybrid, bears considerable similarity to single-pan mechanical balances of the null type. (1)

1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. 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.

Ключевые слова:
balances; scales; weighing instruments; Acceptance criteria/testing; Balances; Laboratory apparatus; Performance--laboratory instrumentation/process; Precision instrumentation; Weight