Maintenance; Recommendations For Correct Operation; Periodical Maintenance; What To Do In Case Of Failure - BASI BFM921 User Manual

Electromagnetic Flowmeter BFM921

6 Maintenance

The inductive flowmeter is an electronic device with circuits protected with built-in electronic fuses. These
protect the instrument against damage caused by the user.

6.1 Recommendations for correct operation

The following principles should be consider during installation:
 If there is a noisy power supply voltage (especially peaks generated, usually by motors, etc.), use an
external power supply filter between the flowmeter and power supply.
 Protect the flowmeter and the internal lining of the sensor pipe from mechanical damage, especially
during installation or cleaning.
 Protect the flowmeter from direct sunlight. Fit a sunshade if necessary.
 Do not expose the flowmeter to intense vibration.

6.2 Periodical maintenance

The flowmeter does not require any special maintenance. Dependent on the media being measured it is
recommended that approx. once a year, remove the sensor from the pipe and clean the liner. Method of
cleaning consists of removing mechanical dirt and any non-conductive coating (like oil film) from the liner.
A very dirty liner could cause inaccuracy of the measurement. Check mechanical state of the liner.

6.3 What to do in case of failure

If an obvious failure occurs during the operation (e.g. the display is not lit), the flowmeter must be switched
off immediately. First, check the fuse located under the electronic board cover.

Turn off the power to the flowmeter.

Remove the cover from the transmitter

The fuse from fuse holder. Replace it with a new fuse of the same rating if necessary

Replace the cover.

Connect power supply again.
If an obvious fault is evident, e.g. a measurement range or an operating mode is not functional, the user cannot
correct the fault.
Hidden faults can cause different symptoms. Usually, they cause instability of some parameters. Hidden
defects can be caused by unacceptable distortion, degraded insulation etc. In this case contact Distributor.
The flowmeter can have "hidden defects", when correct operation rules are not applied. In this case, the fault
can be caused by wrong installation. Most frequent cases of false "hidden defects":
 mains voltage out of tolerance limits or unstable
 poor grounding of the measuring circuit (bad connection of the ground terminal )
 large electrostatic or electromagnetic field.
56
BASI
Operation manual