AUF610 Series Operation Manual
OP610.1.1.5R1ENG
17
2.10 Installation Verification
During the process of the installation, one can: check the receiving signal strength, the signal quality Q
value, the transit time differential of the signals, the estimated speed of sound in the process, the
measured traveling time of the signals and the calculated traveling time ratio. Therefore, optimum
measurement results and successful results can be achieved.
2.10.1 Signal Strength
Signal strength indicates the amplitude of the received ultrasonic signals in the form of an arbitrary 3-digit
number. “000” is no signal detected and 999 indicates that the maximum signal strength available has
been received.
The instrument will provide a reliable measurement if the signal strength ranges from 500 to 999, however
the stronger the signal the better. The instrument continually updates the flow reading by time averaging
the received velocity signal. Therefore a stronger signal ensures fewer situations a signal path is
compromised possibly affecting the overall flow rate and total. The following methods help optimize
signals:
(1) Relocate a more favorable location, if the current location is not good enough for a stable and
reliable flow reading, or if the signal strength is lower than 700.
(2) Try to polish the outer surface of the pipe, and apply more ‘grease’ coupler to increase the signal
strength.
(3) Adjust the transducers both vertically and horizontally while checking the varying signal strength,
stop at the highest position, and then check the transducers spacing to make sure the transducers spacing
is the same as what the M25 shows.
2.10.2 Signal Quality
Signal quality is indicated on the lower right-hand side of the display and denoted as ‘Q’. The higher a Q
value the better the guarantee of a reliable measurement. Under normal pipe condition, the Q value is in
the range 60-90%. Causes for a lower Q value could be:
(1) Interference of other instruments and devices such as high powered electrical equipment working
nearby. Relocate the flow meter to a new place where the interference will be reduced.
(2) Bad sonic coupling for the transducers with the pipe. Try to apply more coupler or clean the surface, etc
(3 )Pipe location is bad. Relocation is recommended.
2.10.3 Total Transit Time and Delta Time
The numbers displayed on menu window M93 are called total transit time and delta time respectively. They
are the raw data the instrument uses to calculate the flow velocity inside the pipe. The flow velocity / rate
indication is a function of the total time and delta time. The total transit time should remain stable or vary
little. If the delta time fluctuates higher than 20%, it means there are probably issues with the transducer
installation.
2.10.4 Time Ratio between the Measured Total Transit Time and the Calculated Time
This ratio would be used to check the transducer installation. If the pipe parameters are entered correctly
and the transducers are installed properly, the value for this ratio should be in the range of 100
±
3. If this
range is exceeded, it should be checked:
(1)
If the pipe parameters are correctly entered.
(2)
If the actual spacing of the transducers is right and the same as what the window M25 shows.
(3)
If the transducers are installed properly in the right directions.
(4) If the mounting location is good and if the pipe has changed shape or if there is too much fouling
inside the pipes.
(5)
Other issues or conditions not conducive to Ultra sonic measurement..
