10. MAINTENANCE
10.3.3 Disagreement Between Indication and Actual Flow
START
Are parameters | NO | |
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set correctly? |
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Set the parameters correctly.
YES
Examine the condition of the fluid in the flowtube, of bubbles, and of grounding.
Was zero | NO | |
adjustment carried out | ||
| ||
correctly? |
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YES |
| |
Is the tube | NO | |
filled completely with |
| |
fluid? |
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YES |
| |
Does the fluid | YES | |
contain bubbles? |
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NO |
| |
Is the | NO | |
flowmeter completely | ||
| ||
grounded? |
| |
YES |
| |
Is the |
| |
signal cable | NO | |
terminal treatment |
| |
complete? |
| |
YES |
| |
Does the | NO | |
conductivity stay within the | ||
| ||
specified range? |
| |
YES |
| |
Is the | YES | |
fluid likely to contain | ||
| ||
deposits? |
| |
NO |
|
Confirm that a valve is located immediately upstream of the flowtube (i.e., on the upstream side).
Is a valve | YES | |
located immediately upstream | ||
| ||
of the flowtube? |
|
NO
Remove the flowtube and examine the insulation resistance.
Signal terminals | NO |
100 M or more? |
|
Excitation terminals |
|
1 M or more? |
|
YES |
|
Examine the operation of the converter using an AM012 calibrator in order to determine whether the fault lies in the converter or in the flowtube.
Execute zero adjustment when the flowtube is filled completely with fluid and when the fluid is not moving.
•Change the mounting position or piping so that the flowtube is
completely filled with fluid.
•Switch to vertical mounting.
Install a defoaming device on the flowtube’s upstream side.
Completely ground the converter and flowtube (Refer to the section on grounding in the relevant user’s manual).
Fully terminate the signal cable using PVC tubing or insulation tape, thus insuring that conductors, inner shields, and outer shields do not make contact with each other or with the case.
Use within the specified conductivity range.
•Remove scales. Especially clean the electrodes and their vincinity.
•Use a soft brush or cloth to perform scale removal, and make sure that the lining is not damaged.
•If any valve located immediately upstream of the flowtube is used in a
• Relocate the valve to the downstream side.
•If the valve must be located on the upstream side, ensure that the minimum distance to the flowmeter is 10 times the
Dry the tube fully to restore insulation resistance.
Contact a service center.
F1007.EPS
IM |
