GF PORTAFLOW 330, Инструкция по эксплуатации

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Troubleshooting Instruction manual
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9 Troubleshooting
9.1 Overview
If you have a problem with your flow monitoring system it can be due to any of the following:
Faulty instrument
If you suspect the instrument is faulty you can check it out using a test block.
This will establish that the instrument is functional and receiving a healthy signal from the
connected transducers.
Incorrect setup
A low, or zero, signal could be caused by incorrect set-up such as:

Incorrect site data entered into the instrument.

Incorrect or non-matching ultrasonic transducers selected for use.
 Incorrectly fitted transducers – lack of couplant applied, incorrect spacing, insecure
attachment.

Poor connections between the probes and the instrument.
Application problem
If you are certain that the instrument is healthy and suitably set-up for the current site; and
the probes are properly assembled and fitted correctly, there could be an application problem
concerned with the site.
Check such conditions such as:
Poor pipe outer surface quality
 Uneven surface preventing good surface contact with the transducer.
 Flaking paint (should be removed).
 Variable air gap in concrete-covered pipes affecting the ultrasonic signal quality.
Poor internal pipe construction

Rough internal pipe walls affecting fluid flow (see roughness factor).

Internal welds positioned in the transducer signal path affecting the signal quality.

The ‘drippings’ in galvanised-dipped pipes or other irregularities interfering with the
signal path.
Incorrect probe location

Transducers located too close to bends or valves, disturbing the flow profile.
 Transducers located too close to insertion probes, disturbing the flow profile.
 For horizontal pipework transducers should not be positioned on the top of the pipe.
Poor fluid conditions within the pipe
 Fluid contains bubbles, high particle density or sludge.

Air in the top of the pipe.
Low fluid flow within the pipe

Pipe obstructions.

Malfunctioning valve not opening fully (or closed inadvertently).