Reset; Diagnostics - GF U3000 V2 Betriebsanleitung

Troubleshooting
10.5

Reset

To reset the flowmeter, carefully insert a straightened paperclip into the pinhole located in the right-hand side of the instrument to
operate the internal reset switch. Hold the paperclip perpendicular to the instrument while doing this.
Note
If the instrument is reset while logging, it is likely that at least some log data will be lost. In addition to this it may also be possible
that some user settings may be corrupted. These settings will be reset to default value when the unit is repowered.
10.6

Diagnostics

This feature is designed for advanced users and is intended to provide information that will aid the user to diagnose problems –
e.g. no signal strength.
When operating in the FLOW or ENERGY READING modes you can access a diagnostics screen by pressing the Diags function key.
This will display the operating values for the following parameters.
Basic diagnostics
ETA (μs)
ATA (μs)
Upstream Fluid Time
Delta T (∆T in ns)
Instantaneous Velocity (m/sec)
Cut-off Velocity (m/sec)
Flow (m/s)
SNR (dB)
Signal (dBV)
Noise (dBV)
Gain (dBV)
Pipe Bore (mm)
Advanced Diagnostics..
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Value the instrument predicts will be the time in μsecs that it should take
for the acoustic wave to propagate across a particular pipe size. This val-
ue is ascertained from the data entered by the user: pipe size, material,
sensor set etc.
Value the instrument measures as the time taken for the acoustic wave
to propagate across the pipe. It is used to see if the signal is being taken
from the burst, at the correct time to get the strongest signal. This value
is normally a few μs below the calculated μs value. If, however, this value
is much greater than the calculated time then there is a problem with the
set-up.
The time the upstream wave spends in the fluid in μsecs.
The difference between the upstream and downstream time in nano-sec-
onds.
Instantaneous fluid velocity.
The current cut-off velocity
Instantaneous volumetric flow in m
Signal to Noise ratio in decibels (dB). A strong signal will generally exhibit
an SNR of greater than 45 dB. A good signal will generally exhibit an SNR
of greater than 40 dB. SNR is literally the difference between the Signal
level and the Noise level in dB.
The unreferenced signal level (in dBV) of the received signal.
The unreferenced background noise level (in dBV) of the received signal.
The gain value (in dBV) represents the amount of amplification that the
received signal has undergone before signal analysis is undertaken. A
large gain figure can indicate that the ultrasonic signal is being strongly
attenuated by something in its path. This could be because of the lack of
couplant, poor sensor alignment or other factors.
The pipe bore (always in mm)
Display the Advanced Diagnostics (see below)
/s to 3 decimal places.
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User Manual