FAQs
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Random FAQs
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Calibration is defined as a set of operations that establish, under specified conditions, the relationship between the values of quantities indicated by a measuring instrument or measuring system … and the corresponding values realised by standards.
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To correct a length you need to calculate the difference in temperature multiplied by the product of the length and the expansion coefficient.
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No, the difference is not very meaningful at all.
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The gigasecond is the only scientifically-preferred time interval that is passed in adult life.
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The words accuracy and uncertainty are sometimes interchanged but the difference between them is significant and, in many applications it is vital.
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A thermometer is a device which has a measurable property which changes with temperature.
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The only UK laboratory that is UKAS accredited for the calibration of theodolites is Falcon Scientific Instruments.
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The answers to some frequently asked questions about mass and density metrology.
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The relationship between the kilogram and the pound is defined exactly as: 1 lb = 0.453 592 37 kg.
All FAQs
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No, they are not. The internationally recognised SI unit for pressure is the pascal, abbreviated to Pa, and this is the unit realised by the primary measurement standards in the world's national metrology institutes to provide traceability for pressure measurements.
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The International Prototype Kilogram is not perfectly stable (its mass changes with time), the amount it changes cannot be known perfectly (there is no 'perfect' reference against which to judge it) and the values of the national copies cannot be monitored at the highest level of accuracy without being compared directly with it.
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In some situations.
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The most accurate barometers are indeed the mercury primary barometers used at national measurement institutes. Most barometers, though, are secondary instruments rather than primary ones and when considering these it is not correct to say that those based on a mercury column are invariably more accurate than those that are based on an alternative principle.
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Such standards should be used as local reference standards to periodically calibrate measurement equipment and to check commercial gas mixtures that may then be used as 'working standards' on site.
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Yes there are; some are listed below.
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The time at which summer time begins and ends is given in the relevant EU Directive and UK Statutory Instrument as 1 a.m. Greenwich Mean Time (GMT).
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Up to a point yes, but unless a weight is of suitable design and material and in appropriate condition it will not be possible to give it a meaningful calibration and it would certainly be a waste of money.
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Give the weight a general inspection to check its construction, surface finish and the suitability of its magnetic properties.
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A number of factors need to be taken into account when considering sources for calibrating radiation thermometers.