INF-TN1FSH-E
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4.4.20. Details of measurement
4.4.20.1. Transit time
Description
The data required for time difference measurement can be set as follows.
[Signal processing outline drawing]
Window
(RWIN)
Ultrasonic
signal
(SIG)
Send start
(TXS)
A. Send signal
Measured
window
Window open
Trigger
Magnified view of B
Signal
Magnified view of A
Send signal
Transmission
voltage
Send pattern
(Example: burst 3)
Trigger level
0 V
1.2 V
1.6 V
-1.2 V
-1.6 V
Detection point
Forward direction ultrasonic total time measurement
Reverse direction ultrasonic total time measurement
Peak of received wave
Sensor send on
upstream side
Sensor receive on
downstream side
Sensor receive on
upstream side
Sensor send on
downstream side
Transmission interval
Note: Make the setting, following the description in “6.3. Checking received waveform.”
CAUTION
•
This parameter is intended for our service personnel.
•
Do not change the setting, since the parameter affects the flow rate measurement. If the setting is
changed, measurement may be disabled.
•
Make the setting when the factory-set value poses problems in flow rate measurement. If no problem
arises with the factory-set value, the setting is not necessary.
Enter data for each item (see the following table) according to the display.
Item
Input method
Function and range or menu
Transmission
count
Selection
The number of transmission of ultrasonic signals per flow rate signal output*
1
(Factory-set value: 128)
•
8, 16, 32, 64, 128, 256
Control method setting of the trigger level (detection point) of ultrasonic
signals (Factory-set value: AUTO)
Selection
•
AUTO
•
MANUAL
Select the detection point according to the rate against the peak of receiving
wave regarded as 100%.
Trigger control
Numeric value
•
Trigger level: 10% to 90%
