Diagnosis When There Is No Receipt Wave Or It Is Weak Or The Receipt Wave Is; Abnormal - Fuji Electric FSZ Instruction Manual

4.3.2.1. Diagnosis when there is no receipt wave or it is weak or the receipt wave is abnormal
When there is no receipt wave or it is weak or the receipt wave shape is abnormal, it is likely that there are incorrect pipe
parameter settings, incomplete installation, fluid and pipe problems, and/or flowmeter failures. Check the following in order.
Incorrect pipe parameter settings
Cause of error
The setting for the outer dimensions is incorrect.
The setting for pipe thickness is incorrect.
The setting for pipe material is incorrect.
The setting for fluid type is incorrect.
Installation is incomplete
Cause of error
The length of the straight pipe is less than specified in
"2.1.1 Conditions on straight pipe".
For horizontal piping, the sensor is not mounted
horizontally or within ±45° of the horizontal surface (for
vertical piping, it can be mounted anywhere on the
outer perimeter).
The sensor is mounted to the welded part of the pipe.
The sensor is not mounted securely to the pipe.
Fluid and pipe problems
Cause of error
Partially filled pipe
Air bubble contamination
● The cause is air-bubble contamination if
measurement is normal when the fluid flow is
stopped.
● If the sensor is mounted immediately after a valve,
cavitation can cause the same phenomenon as air-
bubble contamination.
There is high turbidity
The interior and exterior surfaces of the pipe are rough
due to rust, debris, and deposits.
Scaling on the inside due to old piping
It is a lining pipe
Flowmeter failure
Cause of error
Defective circuit, sensor, etc.
Countermeasure
Please enter it correctly (Refer to "3.8.1Piping parameter
setting method").
Countermeasure
Reinstall it in a place that complies with the straight pipe
length.
Remount the sensor horizontally or within ±45° of the
horizontal horizontal surface (Refer to "2.1.2Mounting
orientation").
Remount it while avoiding the welded part (Refer to
"2.1.2Mounting orientation").
Mount the sensor correctly (Refer to "2.2.1Mounting on
pipes").
Countermeasure
Find a location where the fluid is full in the same pipe line
and move the flowmeter to that location.
● Mount it to the lowest location on the piping line.
Remove the air bubbles.
● Raise the level of the pump well.
● Check the pump shaft seal.
● Tighten the negative pressure pipe flange.
● Do not allow it to cascade down into the pump well.
Move the sensor to a location with no air-bubble
contamination.
● Inlet side of the pump
● Upstream from the valve
Move it to another location or another pipe.
Remove roughness from the exterior surface of the pipe
using a file, etc. ("2.2.1Mounting on pipes").
If there is possibility of rust on the interior surface of the pipe,
reinstall it at a location where it is considered to be rust-free.
Move it to another location or another pipe.
Countermeasure
Go to "4.3.6.Hardware failure countermeasures"
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