Gauges calibration

Verify evidence - Example Is the gauge calibrated and accurate. Eliminate or eaneel other rea.sons or possibilities for the evidence. Example The pump is not pumping enough pressure and we re no longer able to fill that tank. ... 

Ionisation vacuum gauge. Calibration by direct comparison w/ith a reference gauge (CD) 2/91... 

Fig. 7.7. The McLeod gauge. The principles of operation follow. Let the unknown pressure in a system be P when the Hg level is below point 1. Let the volume of the bulb and closed capillary above I be V, which is known. When the mercury is allowed to rise past point I, the gas is trapped and finally compressed into the capillary. Suppose that when the mercury in the reference capillary is at 0, the mercury in the dead-ended capillary is B mm below 0 (i.e., the pressure of the compressed gas is B mm). Since the initial pressure-volume product equals the final pressure-volume product, PV = pv, the volume in thecapillary v will be the height B times the area of the capillary bore A. Thus P = pv/V = B (A/V). Since A and V are known and B is measured, the original pressure (P) may be calculated. Most commercial gauges are provided with a calibrated scale which presents pressures directly. Alternatively, it is possible to devise a linear scale for the McLeod gauge, in one such method the mercury height in the closed capillary is always adjusted to the same point (B0), and then the difference in meniscus heights between the two capillaries is measured (AB). For this case the pressure being measured is P = pv0/V = (B0A/V)AB. As in the previous example, the quantity in parentheses represents the gauge calibration constant.

Verify the calibration of all instrumentation involved in monitoring the EtO cycle. Examples include thermocouple and pressure gauge calibration, gas leak testing equipment, relative humidity sensors, and gas chromatographic instrumentation. 

A chamber, fitted with an ionisation gauge calibrated for N2, is evacuated with a turbomolecular pump (Scff = 150 L s-1, independent of gas type). 

The pressures were measured on a thermocouple gauge calibrated with a McLeod gauge, using dry air. (Pressure gauges and diffusion pumps will be discussed later in this chapter.)... 

A.3.5.7 Relative pressure 15.A.3.5.7.1 This control measures the pressure difference maintained between two adjacent rooms. 15.A.3.5.7.2 The pressure differential is determined by means of an inclined water-gauge calibrated from 1 to 100 Pa (or 0 to 10 mm of water), the room being closed and the air treatment system being balanced and functioning normally. 

Fig. 22.4 Strain gauges calibration procedure (a) static loading for bending moment and axial force strain gauges, (b) static systems, (c) static analyses in ABAQUS-deformed shapes, (d) voltage-mass calibration curve derived for repetitions of the same loading scenario (e) voltage-bending moment calibration curve...

The admission of liquid sample was controlled by using an ionization gauge, calibrated by a capacitance manometer and a variable leak valve. SoUd samples were introduced either through the gas chromatograph or through the solid probe with a heated quartz ampule. 

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