Fluke RPM4 manual 7.2 2READRT, Auto read rate 1on 2off, Pressure Display Rate of Change Update

RPM4™ OPERATION AND MAINTENANCE MANUAL

OPERATION

RPM4’s that have only G100K or G200K Q-RPTs (no Axxx, G15K or BG15K) are NOT equipped with an on-board barometer.

To view the current reading of the on-board barometer press [SPECIAL], <7internal>, <1baro>. The display is in the active pressure unit of measure (see Section 3.3.2). The display resolution is fixed to 0.01 Pa, or its equivalent.

3.5.7.2<2READRT>

PURPOSE

To turn ON and OFF RPM4’s automated, rate of change dependent, reading integration rate feature.

PRINCIPLE

To obtain maximum resolution from RPM4 Q-RPT pressure measurements, an integration time of about 1.2 second per reading is used. In most situations, maximum precision is needed when pressures are stable so a relatively slow display update rate presents no disadvantage. However, when pressure is changing quickly, more rapid pressure updates are usually more important than obtaining maximum precision on individual readings. The RPM4 read rate function automatically adjusts pressure measurement integration time depending on the rate of change of pressure. When pressure is changing rapidly, reading rate is increased. When pressure is evolving slowly, reading rate is decreased and maximum precision is obtained.

When the automated read rate function is ON, three pressure rate of change dependent read rates are used. The result is three display update rates:

Table 10. READRT - Display Update Rates

PRESSURE	DISPLAY
RATE OF CHANGE	UPDATE
> 3 % of range span/s	≈ 0.2 s
> 0.5 and < 3 % of range span/s	≈ 0.6 s
< 0.5 % of range span/s	≈ 1.2 s

For situations in which maximum reading precision is desired regardless of pressure rate of change, the RPM4 automated read rate function can be turned OFF. In this case, the reading rate is always the high resolution rate of about 1.2 readings per second.

OPERATION

To turn the automated read rate function ON or OFF or check its current status, press [SPECIAL], <7internal>, <3ReadRt>.

The display is:

The cursor is on the current selection.

Auto read rate: 1on 2off

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