ABB CK-MAG 10D1477 Instruction Manual page 47

10D1477 MAGNETIC FLOWMETER INSTRUCTION MANUAL
6.3.2 Electrode Check
Due to the unique non-contacting electrode design of this flowmeter, it is not possible to determine
the condition of the metering electrodes with test equipment generally available for field service. If
coil parameters check satisfactorily, proper operation of the signal converter may be verified using a
simulator. Trouble shooting beyond this level must be done by factory personnel.
6.3.3 Primary CMF/BUFFER Board
The Primary CMF/BUFFER board in the model 10D1477 is not field
replaceable. The assembly is easily damaged by static electricity
and also must be cleaned using special processes after soldering
due to the ultra high circuit impedances in the system. If the assem-
bly is suspected to be defective, the entire flowmeter (less con-
verter) must be returned to the factory for repair or replacement.
The Primary CMF/BUFFER Board is located in the base of the electronics housing as shown in
Figure 6-1. This pc board includes the constant meter factor/size network. The constant meter
factor/size network is used to standardize the particular flowmeter; i.e., provide a meter CAL
FACTOR that will be the same for all meters of the same size.
The constant meter factor/size network is factory set by precise calibration prior to shipment. This
calibration procedure (used to establish the exact setting for the particular constant meter factor/size
network) also compensates for variations resulting from manufacturing tolerances. Hence, the value
of constant meter factor/size network on each primary board is unique and may be applicable only for
the particular flowmeter for which it was supplied.
6-4
TABLE 6-1. PRIMARY COIL RESISTANCE
METER SIZE
Inches mm
1 25
1-1/2 40
2 50
3 80
4 100
NOTE
COIL RESISTANCE
Ohms (nominal)
41
60
16
19
21