GE UTX878 Ultrasonic, User Manual

Page: 40 / 103

March 2004
2-16 Programming Site Data
Entering Signal
Parameters
In the Signal submenu, you can set parameters that affect the
transducer signal:
Caution!
The SIGNAL default settings are suitable for most
applications. Consult GE Panametrics before changing
any of these applications.
•
Delta-T Offset
•
Zero Cutoff
•
Errors Allowed
•
Peak Detection Method and Thresholds
•
Transmit Sample Size
•
Velocity Averaging
While following the programming instructions, refer to Figure A-1 on
page A-1 of Appendix A,
Menu Maps .
Note: If you are in the PROG menu, proceed directly to Step 4. If
you scroll to a different option, press [ENT] twice to select
that option (once to enter and again to confirm the selection).
To enter the Signal submenu:
1. Press [ESC]. The UTX878 enters the User Program.
2. Press the [
X
] key until PROG is bracketed and press [ENT].
3. Use the [
S
] and [
T
] keys to scroll to the desired Channel and
press [ENT].
4. Scroll to the Signal option and press [ENT].
5. The first prompt, Delta-T Offset , is the difference between the
upstream and downstream transit times of the transducer signals.
It should normally be set to 0. Press [ENT], use the arrow keys to
enter the new value, and press [ENT] to confirm your entry.
6. The next prompt asks for the Zero Cutoff . Near “zero” flow, the
UTX878 may have fluctuating readings due to small offsets
(caused by factors such as thermal drift in the fluid). The zero
cutoff causes velocity measurements less than the cutoff to be
reported as zero. To set the cutoff, press [ENT], and use the arrow
keys to enter the new value. Press [ENT] to confirm your entry.