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Attempts at standardized temperature measurement prior to the 17th century were crude at best. For instance in 170 AD, physician Claudius Galenus [1]: 18 mixed equal portions of ice and boiling water to create a "neutral" temperature standard.
The most common ion gauge is the hot-cathode Bayard–Alpert gauge, with a small ion collector inside the grid. A glass envelope with an opening to the vacuum can surround the electrodes, but usually the nude gauge is inserted in the vacuum chamber directly, the pins being fed through a ceramic plate in the wall of the chamber. Hot-cathode ...
A dead weight tester (DWT) is a calibration standard method that uses a piston cylinder on which a load is placed to make an equilibrium with an applied pressure underneath the piston. Deadweight testers are secondary standards which means that the pressure measured by a deadweight tester is defined through other quantities: length, mass and time.
This is called a limited calibration. But if the final measurement requires 10% accuracy, then the 3% gauge never can be better than 3.3:1. Then perhaps adjusting the calibration tolerance for the gauge would be a better solution. If the calibration is performed at 100 units, the 1% standard would actually be anywhere between 99 and 101 units.
Pages in category "Pressure gauges" The following 23 pages are in this category, out of 23 total. This list may not reflect recent changes. ...
A particular choice of the scalar and vector potentials is a gauge (more precisely, gauge potential) and a scalar function ψ used to change the gauge is called a gauge function. [citation needed] The existence of arbitrary numbers of gauge functions ψ(r, t) corresponds to the U(1) gauge freedom of this theory. Gauge fixing can be done in many ...
The Pirani gauge is a robust thermal conductivity gauge used for the measurement of the pressures in vacuum systems. [1] It was invented in 1906 by Marcello Pirani. [2] Marcello Stefano Pirani was a German physicist working for Siemens & Halske which was involved in the vacuum lamp industry.
A micrometer, sometimes known as a micrometer screw gauge (MSG), is a device incorporating a calibrated screw widely used for accurate measurement of components [1] in mechanical engineering and machining as well as most mechanical trades, along with other metrological instruments such as dial, vernier, and digital calipers.