GE AquaTrans AT868 User Manual page 40

Transducer
Signal
Parameters Range
–1000 to
Delta T Offset
1000 msec
-100 to
% of Peak
100%
Transmitter Low or High
Voltage
Xmit Sample 2, 4, 8, 16
Size or 32
# of Errors 0 to 16
Minimum
-100 to 100
Peak% Limit
Maximum
-100 to 100
Peak% Limit
Procedure Options
Programming Site Data
Table 2-3: Transducer Signal Settings
Default
Value
An offset between the upstream and downstream transit
0 msec
times is specified at this prompt.
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
- 40%
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.
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
High
fluid.
The LOW setting is normally sufficient. HIGH is usu-
ally selected for large pipes or liquids with one or more
phases.
Both upstream and downstream transducers transmit
ultrasonic pulses in bursts, which consist of a series of
8 transmit pulses. XMIT SAMPLE SIZE determines how
many bursts are sent in one direction before sending in
the other direction.
Use this prompt to enter the number of errors the
8
AT868 can record before it displays an error message.
Use this prompt to enter the minimum percent of peak
-100
that the AT868 can use to measure transit time.
Use this prompt to enter the maximum percent of peak
100
that the AT868 can use to measure transit time.
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.
•
Miscellaneous Information
September 2004
2-15