Panametrics DigitalFlow XGF868i, Руководство для стартапов, Страница: 44 / 90

Chapter 2. Initial Setup
34 DigitalFlow™ XGF868i Startup Guide
2.7.1 Special Transducers
3. Scroll to the transducer Frequency (supplied by the factory) and press
[Enter].
Note: The frequency is required to transmit an excitation voltage at the transducer’s natural frequency.
4. Enter the special transducer Tw (time delay) value (supplied by the factory) and press
[Enter].
Tw is the time required for the transducer signal to travel through the transducer and its cable. This time delay
must be subtracted from the transit times of the upstream and downstream transducers to ensure an accurate
measurement.
2.7.2 Pipe Data
If either a standard or a special transducer is being used, the programming sequence should be rejoined at this
point.
5. To select the appropriate Pipe OD Unit type from the list shown in Table 9 below, scroll to the right side of the
screen, and use the up and down arrow keys to step through the list. Press
[Enter].
Then use the arrow keys to enter
the known pipe outside diameter or circumference on the left side and press
[Enter].
Obtain the required information by measuring either the pipe outside diameter (OD) or circumference at the
transducer installation site. The data may also be obtained from standard pipe size tables found in Sound
Speeds and Pipe Size Data (914-004).
6. Use the arrow keys to enter the known Pipe Wall Thickness (in inches or mm) and press
[Enter].
If the pipe wall
thickness is not available, look up the value in a table of standard pipe size data which can be found in the Sound
Speeds and Pipe Size Data manual (914-004).
Table 9: Available Pipe OD Units
English Metric
inch mm = millimeters
feet m = meters
in/PI = pipe circumference in inches mm/PI = pipe circumference in millimeters
ft/P I= pipe circumference in feet m/PI = pipe circumference in meters