Fluke RPM4 manual Recommended Calibration Point Sequence, Standard Class Q-RPTS, Point Span

5. MAINTENANCE, ADJUSTMENTS AND CALIBRATIONS

5.2.4 RECOMMENDED CALIBRATION POINT SEQUENCE

Calibration adjustments to RPM4 Q-RPTs are made by altering calibration coefficients, PA and PM (see Section 5.2.1.1). To adjust these coefficients to optimum values giving the best results over the Q-RPTs complete operating range, specific calibration point sequences are recommended. The recommended point sequence depends upon whether the Q-RPT being calibrated is a Standard or Premium Class (see Section 1.2.2.1). The class of the RPM4 Q-RPTs is indicated in the model number on the product label and on the rear panel Q-RPT label (<s> for standard, <p> for premium, for example A7Ms or A7Mp).

Prior to running the calibration point sequence, the Q-RPT should be exercised by:

a)Setting full scale pressure.

b)Dwelling at full scale pressure for 5 minutes.

c)Returning to atmospheric pressure (vented). If the Q-RPT is a gas operated Axxx type, use vacuum rather than atmospheric pressure.

d)Dwelling for twenty minutes.

A dwell time after setting the pressure of at least 60 seconds before taking data at each point is recommended.

Section 5.2.4.1 gives calibration point sequences for Standard Class Q-RPTs and Section 5.2.4.2 gives calibration point sequences for Premium Q-RPTs.

It is not required that the calibration pressure standard apply precisely the nominal pressure value of each calibration point as long as the exact value of the applied pressure is known. Best results are obtained if the actual applied pressure is within 2 % of the recommended nominal point.

5.2.4.1STANDARD CLASS Q-RPTS

See additional information in Section 5.2.4 concerning exercising the Q-RPT and dwell time at pressure points.

Table 22. Calibration Point Sequence, Standard Class,

Axxx and Gxxx Q-RPTs

CALIBRATION	POINT
SEGMENT	NO.
	1
Ascending	2
	3
	4
	5
	6
Descending	7
	8
	9

POINT

[% OF SPAN]

Lowest Pressure1

25%

50%

75%

100%

75 %

50 %

25 %

Lowest Pressure1

1.In absolute mode, the lowest point that can be set reliably by the reference piston gauge, or atmospheric pressure for ranges > A1.4M. Zero (vented) in gauge mode.

Axxx (absolute) Q-RPTs that will NOT be used in absolute or negative gauge measurement modes may be calibrated in gauge measurement mode with a gauge pressure standard. Axxx (absolute) Q-RPTs calibrated in gauge measurement mode should be used in gauge mode only (see Sections 3.3.3,

PRINCIPLE, 5.2.5).

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