Endress+Hauser Silometer FMC 672 Z, Инструкция по установке и эксплуатации

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4.4 Level offset
Level offset The calibration (or linearization) determines the level displayed at V0H0/V4H0 for a
particular head of liquid. By entering a level offset at V3H4 for channel 1 or V7H4 for
channel 2 the displayed value can be corrected by the value entered.
•
The offset is subtracted from the measured value
•
It must be entered in the units you have used for calibration
•
All values, including analog signals and relay settings must be changed to
follow the corrected measurement.
For example, after a dry calibration it is decided that the true volume measured from the
bottom of the tank is to be measured, i.e. when the liquid reaches the calibrated zero
level, the display must indicate say 250 m
3
. The value -250 is entered:
Step Matrix Entry Significance
1 V3H4 e.g. -250 Enter amount by which the display is to be corrected in
the units used for calibration or linearisation
-
for channel 2 enter value at V7H4
2 - »E« Registers entry
3 V0H0/V4H0
…
The corrected value is displayed(i.e. +250)
Note!
•
The offset can also be used to correct the zero point of a linearization. In this case
the offset is first subtracted from the »level« displayed at V0H9/V4H9 and the result
converted to the volume displayed at V0H0/V4H0.
BA064E27
After offset
Volume 250m
3
Display 250 m
3
Before offset
Volume 250 m
3
Display 0.000
Fig. 4.3:
Effect of level offset on display at
V0H0/V4H0
Silometer FMC 672 Z/677 Z Chapter 4: Calibration and Operation
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