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The formal definition of calibration by the International Bureau of Weights and Measures (BIPM) is the following: "Operation that, under specified conditions, in a first step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties (of the calibrated instrument or ...
Military instruments as a class draw on most of the categories of instrument described throughout this article, such as navigation, astronomy, optics, and imaging, and the kinetics of moving objects. Common abstract themes that unite military instruments are seeing into the distance, seeing in the dark, knowing an object's geographic location ...
Instruments should be calibrated against a standard instrument that is known to be accurate, and ideally the calibration should be repeated at intervals. The most rigorous standards are those maintained by a standards organization such as NIST in the United States , or the ISO in Europe.
A national measurement system (NMS) is a network of laboratories, calibration facilities and accreditation bodies which implement and maintain a country's measurement infrastructure. [8] [9] The NMS sets measurement standards, ensuring the accuracy, consistency, comparability, and reliability of measurements made in the country. [58]
In industrial instrumentation, accuracy is the measurement tolerance, or transmission of the instrument and defines the limits of the errors made when the instrument is used in normal operating conditions. [7] Ideally a measurement device is both accurate and precise, with measurements all close to and tightly clustered around the true value.
Certified reference materials (CRMs) are 'controls' or standards used to check the quality and metrological traceability of products, to validate analytical measurement methods, or for the calibration of instruments. [1] A certified reference material is a particular form of measurement standard.
A multimeter (also known as a volt-ohm-milliammeter, volt-ohmmeter or VOM) [1] is a measuring instrument that can measure multiple electrical properties. [ 2 ] [ 3 ] A typical multimeter can measure voltage , resistance , and current , [ 4 ] in which case can be used as a voltmeter , ohmmeter , and ammeter .
Ideally the measuring device should not affect the circuit parameters i.e., the internal impedance of the ammeter should be zero (no voltage drop over the ammeter) and the internal impedance of the voltmeter should be infinite (no current through the voltmeter). However, in actual case, ammeters have a low but non zero impedance and voltmeters ...