GE UTX878 Ultrasonic, User Manual

Page: 41 / 103

Programming Site Data 2-17
March 2004
Entering Signal
Parameters (cont.)
7. The Errors Allowed prompt specifies the number of errors the
UTX878 can record before displaying an error message. Press
[ENT], and use the [
S
] and [
T
] keys to scroll to the appropriate
number of errors (from 0 to 16). Press [ENT] to confirm your
entry.
8. The next prompt asks for the Peak Detection method. In the
“Peak” method, the peak is identified by testing a derivative of the
signal. In the “Threshold” method, the peak is identified as the
point where the signal crosses a threshold that is a percentage of
the maximum signal detected. The peak method is more reliable in
identifying the signal in dynamic conditions, while the threshold
method is more reliable in marginal signal conditions.
Note:
Do not change the peak detection method or values unless
recommended by GE Panametrics.
a. Press [ENT]. The screen shows the two display options, Peak
and Threshold. Scroll to the desired option, and press [ENT].
b. The next screen depends on your selection in Step a.
•
If you select Peak , no further options are available. Press [ESC]
to return to the Signal menu.
•
If you select Threshold and press [ENT], the screen shows three
parameters: Min Threshold, Max Threshold and Percent of
Peak. For each parameter, press [ENT]. Use the arrow keys to
enter the new value, and press [ENT].
9. The next parameter is the Transmit Sample Size , the number of
pulses each transducer (upstream and downstream) emits. It is set
to 8 by default. Press [ENT], and use the [
S
] and [
T
] keys to
scroll to the new number (from 1 to 32). Press [ENT] to confirm
the entry.
10. The final prompt asks for Velocity Averaging , in which users
select a certain number of velocity measurements to average
together to smooth out noise in the signal. Press [ENT], and use
the [
S
] and [
T
] keys to scroll to the desired number. (Selections
include none, 2, 5, 10, 30, 60 and Statistics. The Statistics option
increases averaging under steady flow conditions, but allows for a
rapid response to step changes in flow rate.) Press [ENT] to
confirm your entry.
You have completed entering parameters in the Signal option. Press
[ESC] until you return to the PROG menu, or continue pressing
[ESC] until the display screen reappears.