Fluke RPM4 manual Negative Gauge, Differential, Measurement mode 1abs 2gage 3neg gage

RPM4™ OPERATION AND MAINTENANCE MANUAL

Gauge	Measures pressure relative to atmosphere (zero is ambient pressure).
	Range is from zero gauge to full scale, full scale must be greater than zero.
Negative Gauge	Measures pressure relative to atmosphere (zero is ambient pressure).
	Range is positive and negative from zero, negative to minus one
	atmosphere and positive to full scale. With a BGxxx RPT, negative range
	is the negative equivalent of the positive range.
Differential	Available only for the Hi Q-RPT in RPM4s equipped with two Q-RPT modules
	of the same type (Axxx, Gxxx, BGxxx). Measures the difference between the
	Hi and the Lo Q-RPT (Differential = Hi – Lo). Differential measurement mode
	is selected “on top of” the Hi Q-RPT’s base measurement mode (gauge,
	absolute or differential). Differential range is positive to maximum pressure of
	the Hi Q-RPT and negative to the minimum pressure of the Lo Q-RPT base
	measurement mode (see Section 3.3.3.1 for specific information on operation
	in differential measurement mode).

Which measurement modes are available depends on the type of Q-RPT type(s) available. There are three types of Q-RPTs:

Axxx Q-RPTs with designators starting with “A” measure pressure relative to a sealed vacuum reference and are intrinsically absolute. Axxx Q-RPTs support measurement in absolute, gauge and negative gauge modes. Gauge and negative gauge modes are accomplished by offsetting of atmospheric pressure with dynamic compensation for atmospheric pressure changes between offsets using an on-board barometer (see Section 3.2.2). Access to absolute and negative gauge operation can be turned OFF (see Section 5.2.5). In RPM4s with two Axxx Q-RPTs, differential measurement mode is supported on the Hi Q-RPT.

Gxxx Q-RPTs with designators starting with “G” measure positive pressure relative to the TEST(-)port that is connected to atmosphere. Gxxx Q-RPTs support measurement in gauge mode only. In RPM4s with two Gxxx Q-RPTs, differential measurement mode is supported on the Hi Q-RPT.

BGxxx Q-RPTs with designators starting with “BG” measure positive and negative pressure relative to the TEST(-)port that is connected to atmosphere. BGxxx Q-RPTs support measurement in gauge and negative gauge modes. In RPM4s with two BGxxx Q-RPTs, differential measurement mode is supported on the Hi Q-RPT.

When changing modes for a range, if the full scale of the range is 700 kPa (100 psi) or greater, the full scale is the same in both absolute and gauge modes. If the full scale is less than 700 kPa (100 psi), the gauge mode full scale is 100 kPa (14.5 psi) lower than the absolute mode full scale. If the absolute mode full scale is less than 100 kPa (14.5 psi), there is no gauge mode available. Gauge and negative gauge modes, when available, always have the same full scale.

Measurement mode selection is range specific.

OPERATION

See Section 3.3.3.1 for information on differential mode operation. Differential mode operation is only available for the Hi Q-RPT in RPM4s that are equipped with two Q-RPTs of the same type (Axxx, Gxxx, BGxxx).

To change the active measurement mode for a range, press [MODE] from the MAIN RUN screen while the range is active. The display depends upon the type of Q-RPT that is active.

Measurement mode: 1abs 2gage 3neg gage

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