Technical Manual MIVI 9612
Réf. 254-31/0
6
1.3. Checking the equipment at the receipt
a) At first, check the supply conformity with the ordered equipment, mainly the presence of the
parts necessary for the equipment mounting. Those to be used at the process will be given to
the concerned department, for the installation preparation.
b) Place the sensor on a soft foam plate, connect it to processor (see §3.10) and switch on. The
vibration appears at the rod, the viscosity indication is close to zero (or close to the minimal
required current value of the analog output). When touching the rod, the information has to
increase.
In case of subnormal operation a) or b), check as follows :
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Power supply, connections, cables,
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The good condition of the vibrating rod (no bending on knock damages).
Consult your distributor.
1.4. Checking the equipment when placed at the process
Before filling the network check that the viscosity information is stable (vibrating rod in air). If
not, check the strength of the sensor fitting, then rotate the sensor of 90° (4 possible positions).
Choose the position where the information is the most stable.
Locate this position, in order to restore it when the sensor is removed – put in place.
Adjust the mounting offset, at room temperature. The rod is vibrating in air.
When possible, note the viscosity information when a cleaning or rinsing solution is flowing.
If the original calibration is convenient, one of the 2 above mentioned values can be taken as
reference for periodic control of the equipment operation each time that the same conditions will occur
(rod in air, or in the cleaning solution). Such an operation can be assimilated to a self-checking.
If the original calibration has been modified the reference values will be of course those
obtained with the new calibration.
1.5. Periodic checking
Conformity to regulations relative to Quality Insurance implicates a periodic control of the
measuring equipment used in the manufacturing operations, taking in consideration (or correcting)
their drift in time.
It is proved that this equipment drift is negligible. However, it is good to check their aspect and
their response once a year, at the same time as the other process equipment.
A fast test is many times available, when the sensor active part is in air, or immersed in a
cleaning or rinsing solution. As long as these values stay similar, we can say that the sensor
operation is right among its whole range (if no intermediate re-programming occurred).
1.5.1. Offset adjustment in air
The clean and dry rod is vibrating in air when the offset adjustment is carried out.
The amplitude, corrected in offset, Vbrut, must be shift to the reference of 900 mV.
See User Manual §5.1.
