DigitalFlow™ GC868 Startup Guide (1 and 2-Channel)
2-6
Chapter 2. Initial Setup
2.6 Entering Pipe
Data
The
PIPE
submenu permits entry of the transducer and pipe specifications. To
program this menu, complete the following steps:
1.
At the
User
(or
Channel) Program
screen, press
[F3]
to program the
PIPE
submenu.
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.
2.6.1
Special
Transducers
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.
Press
[F2]
to select Shear wave as the
Transducer Type
.
Note:
While three choices are available (Rayleigh, Shear wave or wetted
transducers), the GC868 is designed for use with Shear wave clamp-on
transducers. Consult the factory before selecting Rayleigh or wetted
transducers.
c.
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.
d.
Enter the special transducer
Time Delay (Tw)
value supplied by the factory.
Press
[ENT]
. (The meter will only accept values from 0 to 1,000
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.
e.
Press
[F1]-[F4]
to select the
Wedge Material
. The available options include
VHT
(very high temperature),
MT
(medium temperature),
HT
(high
temperature) and
OTHER
. Refer to the data sheet supplied with your
transducer to determine the appropriate setting.
• If you selected
use the numeric keys to enter the
Wedge
Soundspeed
in ft/sec or m/sec and press
. The meter proceeds to
step 3.
f.
Use the numeric keys to enter the
Wedge Angle
(the angle of the ultrasonic
transmission) in degrees and press
[ENT]
.
2.6.2 Wedge
Temperature
3.
Use the numeric keys to enter the
Wedge Temperature
in deg F and press
[ENT]
.
The wedge temperature is an average temperature of the pipe wall temperature
and the ambient temperature.
2.6.3 Pipe Material
4.
Press
[F1]-[F4]
to select the
Pipe Material
. Press
[
→
]
to access additional options,
as listed in Table 2-4 below.
Table 2-4: Pipe Materials
Pipe Material Category
Specific Material
Steel
Carbon Steel or Stainless Steel
Iron
Ductile Iron or Cast Iron
Cu - Copper
None
Al - Aluminum
None
Brass
None
CuNi - Copper/Nickel
70% Cu 30% Ni or 90% Cu 10% Ni
Glass
Pyrex, Flint, or Crown
