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4.1
Signal Strength
•
Signal strength indicates the amplitude of receiving ultrasonic signals by a 3-digit
number. [000] means there is no signal detected and [999] refers to the maximum
signal strength that can be received.
•
The following methods are recommended to obtain stronger signals:
1.
Relocate a more favourable 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 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
spacing of the transducers to make sure the spacing of the transducers.
4.1.1
Signal Quality
Signal quality is indicated by the Q value in the instrument. A higher Q value means high
signal to noise ratio (SNR), which provide higher degree of accuracy in measurement.
Under normal pipe condition, the Q value is in the range between 600-900, the higher the
better.
Disadvantage of lower Q value is as follows:
1.
Interference of other instruments and devices such as a powerful transmitter
working nearby. Try to relocate the flow meter to a new place where the
interference can be minimum. Bad sonic coupling for the transducers with the
pipe.
2.
Apply more coupler or clean the surface, etc. Pipes are difficult to be
measured. Relocation is recommended.
4.2
Transmitter Connections
4.2.1
Basic Circuit of the Transmitter
The converter can supply the uncontrollable current to the coil in the sensor of
electromagnetic flow meter. The head amplifier amplifies the electromotive force from
the sensor and converts it into standard signals of current or frequency so that the
signals can be used for displaying, controlling, and processing.
4.3
Digital Output
The transmitter has two output signals i.e., frequency and pulse output. The user can
choose only one type of output.
4.3.1
The Connection of Digital Output
Digital output has two connected points i.e., digital output connected point and digital
ground point,
