Adjustment; Zero Point Adjustment - Endress+Hauser Cubemass DCI Operating Instructions Manual

Commissioning
"
60
6.5

Adjustment

6.5.1

Zero point adjustment

All measuring devices are calibrated with state-of-the-art technology.
The zero point obtained in this way is printed on the nameplate.
Calibration takes place under reference operating conditions → ä 86.
Consequently zero point adjustment is generally not necessary for Cubemass DCI!
Experience shows that the zero point adjustment is advisable only in special cases:
• To achieve highest measuring accuracy also with very small flow rates.
• Under extreme process or operating conditions (e.g. very high process temperatures).
Preconditions for a zero point adjustment
Note the following before you perform a zero point adjustment:
• Adjustment can only be performed on homogeneous fluids.
• Zero point adjustment is performed at zero flow (v = 0 m/s). This can be achieved, for example,
with shutoff valves upstream and/or downstream of the sensor or by using existing valves and
gates.
– Normal operation → valves 1 and 2 open
– Zero point adjustment with pump pressure → Valve 1 open / valve 2 closed
– Zero point adjustment without pump pressure → Valve 1 closed / valve 2 open
Fig. 37: Zero point adjustment and shutoff valves
Caution!
• The currently valid zero point value can be viewed using the "ZEROPOINT" function
(È "Description of Device Parameters" manual).
Cubemass DCI MODBUS RS485
2
1
A0003601
Endress+Hauser