Example of editing limits
for pressure sensor
0…10 bar
Note!
If a reversal of action from the current
output
to
the
measured
pressure
is
required (inverted output) i.e. the 4 mA
calibration value corresponds to the upper
range-value and the 20 mA calibration
value
corresponds
to
the
lower
range-value, then the calibration should be
carried out as follows:
#
Matrix Path through
the menus
Entry
Main group: Basic setting
1
Enter value for upper range-value
V0H2
➤
Sets 20 mA
e.g. –1 bar
Confirm
2
Enter known pressure for lower range-value
V0H1
➤
Sets 4 mA
e.g. 1 bar
Confirm
3
Enter known pressure for upper range-value
V0H2
➤
Sets 20 mA
e.g. 0 bar
Confirm
Editing limits for
zero correction and
recalibration
There are also editing limits for the "Low Sensor Trim" (V7H4), "High Sensor Trim" (V7H5)
and "Zero Correction" (V9H5) parameters. For the parameters, the editing limits are
defined by the sensor limits and the applied pressure.
To carry out a recalibration or a zero correction, the device must have a reference
pressure (Refer to Chapter 6.1, Section on "Zero Correction" and Chapter 9.5
"Recalibration"). Enter a value assigned to the applied pressure using the relevant "Low
Sensor Trim" (V7H4), "High Sensor Trim" (V7H5) or "Zero Correction Value" (V9H5)
parameters.
•
Calculation of the value for the lower editing limit of V7H4, V7H5 and V9H5:
"Sensor Pressure" (V7H8) – 10% of the sensor end value
•
Calculation of the value for the upper editing limit of V7H4, V7H5 and V9H5:
"Sensor Pressure" (V7H8) + 10% of the sensor end value
The "Sensor Pressure" parameter (V7H8) shows the applied pressure on the device.
#
Example:
1
Sensor: 0…10 bar (Sensor end value = 10 bar)
applied pressure = "Sensor Pressure" (V7H8)
= 0.1 bar (e. g. depending on position)
2
The applied pressure (V7H8) can be
assigned to a value between the upper and
lower editing limits using the "Zero Correction"
(V9H5) parameter. In this example values
from –0.9 bar to 1.1 bar.
Value for lower editing limit, V9H5 =
"Sensor Pressure" – 10% of sensor end value
0.1 bar – 0.1
•
10 bar = 0.1 bar – 1.0 bar =
–0.9 bar
Value for upper editing limit, V9H5 =
"Sensor Pressor" + 10% of sensor end value
0.1 bar + 0.1
•
10 bar = 0.1 bar + 1.0 bar =
1.1 bar
Note!
-1
0
10
11
Maximum measuring range
Set span = 8 bar
Set span = 8 bar
Low Sensor Limit (V7H6)
Pressure sensor: 0 bar…10 bar
Lower editing limit
High Sensor Limit (V7H7)
Upper editing limit
10% of
"High
Sensor
Limit"
10% of
"High
Sensor
Limit"
7 Diagnosis and Trouble-Shooting
Cerabar S
42
Hauser
