8. F 500: MEASUREMENT SETTINGS
In order to compensate a potential drift of the transmitter, it is possible to add an offset to value displayed by the
transmitter.
Adding an offset is only possible for the measured parameters (temperature, humidity, pressure, air velocity, ...). It is not
possible to add one for the calculated parameters (airflow, psychrometry,...).
8.1. Auto-zero (CP210-R)
Class 210 pressure transmitters have an auto-zero which guarantees a good reliability of the measurement in high and low
ranges.
The auto-zero compensates for any long-term drifts of the sensitive element, with the manual adjusting of the zero.
To perform a self-calibration:
➢
Unplug the 2 pressure connection tubes.
➢
Press auto-zero button. (See
“Connection”
on the data sheet).
If the instrument has a display, it is possible to perform an auto-zero pressing for 3 seconds the
“Esc” key. “AutoZ” is displayed briefly meaning the auto-zero has been well performed.
On the CP211-R and CP212-R transmitters, it is not necessary to unplug the 2 pressure connection
tubes (see chapter 8.3).
8.2. Pressure measurement integration (CP210-R)
This function is available on CP210-R transmitters only.
The pressure measurement element is very sensitive and reacts to pressure changes. When making measurements in
unstable air movement conditions, the pressure measurement may fluctuate. The integration coefficient (from 0 to 9) makes
an average of the measurements; this helps to avoid any excessive variations and guarantees a stable measurement.
New displayed value =
[((10 - Coef.) x New value) + (Coef. x Old value)] /10
Example: CP212-R (0-1000 Pa) – Current measurement: 120 Pa – New measurement: 125 Pa
The pressure source being stable, the user selects a low integration. Integration: 1, maximum admitted variation ±10 Pa.
The variation is lower than 10 Pa, it is possible to apply the integration calculation formula.
Next displayed value:
((9 * 125) + (1 * 120))/10 = 124.5 i.e, 124 Pa. If the new measurement had been 131 Pa, the
next displayed value would have been 100% of the new value i.e, 131 Pa.
The transmitter is powered on.
➢
Press
OK
.
➢
Enter the activation code (see page 8).
➢
Press
OK
.
➢
Press
Up
key to go to folder
“F 500”
.
➢
Press
OK
.
➢
Set the integration value with
Up
and
Down
keys.
This value must be between 0 and 9 with:
•
Coefficient 0:
no integration, important fluctuation of the displayed value.
•
Coefficient 9:
maximum integration, more stable measurement display.
8.3. Time-delay between two auto-zeros (CP211-R and CP212-R)
On transmitters having a solenoid valve for auto-zero (CP211-R and CP212-R), it is possible to set an interval between 2
auto-zeros:
The transmitter is powered on.
18
F 500: MEASUREMENT SETTINGS
