Search results
Results from the WOW.Com Content Network
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 ...
Ruby spectra R1, R2 lines. The ruby fluorescence pressure scale is an optical method to measure pressure within a sample chamber of a diamond anvil cell apparatus. [1] Since it is an optical method, which fully make use of the transparency of diamond anvils and only requires an access to a small scale laser generator, it has become the most prevalent pressure gauge method in high pressure ...
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 ...
Strain-Gauge: Strain gauge based pressure sensors also use a pressure sensitive element where metal strain gauges are glued on or thin-film gauges are applied on by sputtering. This measuring element can either be a diaphragm or for metal foil gauges measuring bodies in can-type can also be used.
The Pressure Equipment Directive (PED) 2014/68/EU (formerly 97/23/EC) [1] of the EU sets out the standards for the design and fabrication of pressure equipment ("pressure equipment" means steam boilers, pressure vessels, piping, safety valves and other components and assemblies subject to pressure loading) generally over one liter in volume and having a maximum pressure more than 0.5 bar gauge.
A rising pressure in the vessel results in the PCV opening to feed more gas forward. If the pressure continues to rise some controllers then act to open a second PCV that feeds excess gas to the flare system. The pressure transmitter is configured to provide warning alarms (PAL and PAH) if the pressure exceeds set high and low limits.
Gauges for measuring pressure in the range 20–30 standard atmospheres (15,000–23,000 mmHg) have been built. [13] A 23-metre-tall mercury column is difficult to read and suffers from inaccuracies caused by different parts of the column being at different temperatures. A more compact mercury pressure gauge suitable for high pressure was built ...
A special form of the Pirani gauge is the pulsed Pirani vacuum gauge where the sensor wire is not operated at a constant temperature, but is cyclically heated up to a certain temperature threshold by an increasing voltage ramp. When the threshold is reached, the heating voltage is switched off and the sensor cools down again.