Chapter 2. Initial Setup
2-7
DigitalFlow™ GC868 Startup Guide (1 and 2-Channel)
• Depending on the pipe material choice, another prompt may ask you to select
the
Specific Material
.
• If you have selected “Other,” enter the pipe material
Sound Speed.
Press
[ENT].
2.6.4 Pipe OD
5.
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 required pipe data may be obtained 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 (see the Panametrics document
Sound Speeds and Pipe Size Data,
#916-004). For a list of the available English and
Metric units and their definitions for the
PIPE OD
prompt, refer to Table 2-5 on page
2-7.
2.6.5 Pipe Wall
6.
Enter the known thickness of the
Pipe Wall
, in the same units used for the pipe
OD. Press
[ENT]
. (The meter will only accept values from 0 to 4 in., or
0 to 100 mm.)
If the pipe wall thickness is not known and cannot be conveniently measured, look
up the value in a table of standard pipe size data or use the Model GC868’s on-line
Help Menu
.
2.6.6 Fluid Type
7.
Press
[F1]
= natural gas,
[F2]
= air,
[F3]
= steam, or
[F4]
= any other gas to
select the
Fluid Type.
If
OTHER
was selected, enter the speed of sound (in feet per
second) in the gas to be measured. Press
[ENT]
. (The meter will only accept
values from 125 to 9,000 ft/sec, or from 38.1 to 2,743.2 m/s.)
2.6.7 Reynolds
Correction
8.
The
Reynolds Correction
factor is a number based on the kinematic viscosity
and flow rate of the gas. At the
prompt, press
[F1] to turn Reynolds Correction
off,
or
[F2] to turn it on.
a.
If you select Reynolds Correction, the GC868 asks for the
Kinematic Viscosity
of
the gas (available in the brochure
Sound Speeds and Pipe Size Data
, 914-004).
Use the numeric keys to enter the desired value and press
[ENT]
.
2.6.8 Calibration Factor
9.
Enter a value for the flow
Calibration Factor
and press
[ENT]
. The default value is
1.00. (The meter will only accept values from 0.5000 to 2.0000.) If you are using
wetted transducers, you have completed programming in the
PIPE
menu.
2.6.9 Number of
Traverses
10.
Press
[F1]-[F4]
to select the desired number of traverses (times the ultrasonic
signal traverses the pipe, from 1 to 9).
Note:
Most clamp-on gas applications require a single traverse (1(Z)).
Plastic
Nylon, Polyester, Polypropylene, PVC
(CPVC), Acrylic
Other*
Any material
Table 2-4: Pipe Materials
Pipe Material Category
Specific Material
Table 2-5: 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
