DH Instruments E-DWT-H, Руководство по эксплуатации и обслуживанию

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E-DWT-H OPERATION AND MAINTENANCE MANUAL
© 2009 DH Instruments, a Fluke Company Page 68
3.9.7.2 <2READRT>
 PURPOSE
To turn ON and OFF RPM4-E-DWT’s automated, rate of change dependent,
reading integration and display rate feature.
 PRINCIPLE
To obtain maximum resolution from RPM4-E-DWT 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-E-DWT 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 8. READRT – display update rates
PRESSURE
RATE OF CHANGE
DISPLAY
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-E-DWT 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] , <7intern> , <2ReadRt> .
The display is:
Auto read rate:
1on 2off
The cursor is on the current selection.
Selecting <1on> activates the automated reading rate and returns to the MAIN
RUN screen. Selecting <2off> turns OFF the automated reading rate and
returns to the MAIN RUN screen.
The default RPM4-E-DWT condition is auto read rate ON.
Note
Auto read rate ON/OFF is NOT Q-RPT or range specific. Turning
auto read rate ON or OFF in one range turns it ON or OFF for all
RPM4-E-DWT ranges.
3.9.7.3 <3RPT2X>
 PURPOSE
This feature is not used in this RPM4-E-DWT model.