GE AquaTrans AT868, User Manual

Page: 40 / 158

Programming Site Data 2-15
September 2004
Procedure Options
After completing the above steps, the user program returns to the
SET UP
window. Do one of the following:
•
To continue regular programming, refer to Appendix A, Menu
Maps , to navigate to the desired menu.
•
To leave the user program, press
[ESC]
four times.
Delta T Offset
–1000 to
1000 msec
0 msec
An offset between the upstream and downstream transit
times is specified at this prompt.
% of Peak
-100 to
100%
- 40%
The percentage of peak used to calculate the transit
times and Delta T is specified at this prompt.
Note:
This setting is a starting point for detecting the
signal. The meter will automatically adjust this
value if the calculated transit time is
unacceptable. You can set the limits for this
value using the
MIN. PEAK%
and
MAX. PEAK%
discussed at the end of this table.
Transmitter
Voltage
Low or High High
The transmitter voltage can be set to low or high to
reduce power consumption. LOW (default setting) is
typically selected for smaller pipes with a single-phase
fluid.
The LOW setting is normally sufficient. HIGH is usu-
ally selected for large pipes or liquids with one or more
phases.
Xmit Sample
Size
2, 4, 8, 16
or 32
8
Both upstream and downstream transducers transmit
ultrasonic pulses in bursts, which consist of a series of
transmit pulses.
XMIT SAMPLE SIZE
determines how
many bursts are sent in one direction before sending in
the other direction.
# of Errors 0 to 16 8
Use this prompt to enter the number of errors the
AT868 can record before it displays an error message.
Minimum
Peak% Limit
-100 to 100 -100
Use this prompt to enter the minimum percent of peak
that the AT868 can use to measure transit time.
Maximum
Peak% Limit
-100 to 100 100
Use this prompt to enter the maximum percent of peak
that the AT868 can use to measure transit time.
Table 2-3: Transducer Signal Settings
Transducer
Signal
Parameters Range
Default
Value Miscellaneous Information