PG7000 High Line Differential Mode for Defining Differential Pressure at Line Pressures Above Atmospheric Pressure (PG7000 V2.03 and higher) Technical Note

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PG7000 High Line Differential Mode for Defining Differential Pressure at Line Pressures Above Atmospheric Pressure (PG7000 V2.03 (1.42 MB)

Pressure measuring devices intended to measure differential pressure at line pressure well above atmospheric pressure are widely used. These are often calibrated in gauge mode, leaving the low side open to atmosphere and applying known pressures relative to atmosphere to the high side. However, the very high ratios of the line pressure to atmospheric pressure and to the differential pressure are likely to cause significant differences in the device’s response to differential pressure when operating at atmosphere and at the normal elevated line pressure. Applying a common pressure simultaneously to both sides of the device easily quantifies changes in zero with line pressure. To determine the influence of line pressure on differential pressure span, a pressure standard able to define differential pressures at elevated line pressures must be available. To be useful, the standard must have measurement uncertainty lower than the target uncertainty of the device under test