Panametrics DigitalFlow GS868, Programming Manual, Page: 23 / 146

DigitalFlow™ GS868 Programming Manual (2-Channel) 13
Chapter 1. Programming Site Data
1.7.3 Entering Pipe Data
Enter the transducer and pipe parameters via the PIPE submenu. While following the programming instructions, refer
to the menu map in Figure 11 on page 83 in Appendix A,
Menu Maps.
1. At the Channel Program screen, press [F3] to program the PIPE submenu.
1.7.3.1 Transducer Number
2. Enter the Transducer Number (normally engraved on the head of the transducer). Press [ENT] . If there is no
engraved number, complete the steps below. Otherwise, proceed to step 3.
IMPORTANT: Special transducers, which have no engraved number on the head, are rarely used. Examine the
transducer head carefully for a number.
a.
Assign a number between 91 and 99 to the
Special Transducer and press [ENT]
. (The meter will only accept values
from 1 to 199.)
b. Use the


] and [F1]-[F4] keys to select the Frequency of the special transducer. The meter can not
transmit an excitation voltage at the transducer’s natural frequency without this data.
c. Enter the special transducer Time Delay (Tw) value supplied by the factory. Press [ENT] . (The meter will only
accept values from 0 to 1000

sec.)
Note:
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.
1.7.3.2 Pipe OD
3. Enter the known Pipe OD or circumference and use the [F1]-[F4] keys to select the appropriate units. Press [ENT].
(The meter will only accept values from 1/8 to 648 in.) The option bar choices may appear in English or Metric
units.
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. Table 4 below lists the
available English and metric OD units, as specified in the GLOBL submenu.
1.7.3.3 Pipe Wall
4. Use the numeric keys to enter the known thickness of the
Pipe Wall. Press
[ENT] .
If the pipe wall thickness is not available, look up the value in a table of standard pipe size data or use the Model
GS868’s on-line Help Menu
1.7.3.4 Path Length
5. Press [F1] = inch or [F2] = feet to select the units. Then, enter the Path Length (P) of the ultrasonic signal. Press
[ENT] . (The meter will only accept values from 1/8 to 900 in.)
Note:
The factory has calculated both the transducer signal path length
(P)
and the transducer signal axial length
(L)
, based on the exact transducer configuration used for the application. These values are engraved on the
flowcell and/or are included in the documentation supplied with the meter.
1.7.3.5 Axial Length
6. Press [F1] = inch or [F2] = feet to select the units.Then, enter the Axial Length (L) of the ultrasonic signal and press
[ENT] .
Table 4: Available Pipe OD Units
English Metric
inch = pipe OD in inches mm = pipe OD in millimeters
feet = pipe OD in feet m = pipe OD in meters
in/PI = pipe circumference
in inches
mm/PI = pipe circumference
in millimeters
ft/PI = pipe circumference
in feet
m/PI = pipe circumference
in meters