April 2004
9-26 Servicing the PT878GC
Setting up Signal Parameters
1. Press the [T] arrow key to enter the window.
2. The first prompt asks for the Delta-T offset. Delta-T is the
difference between the upstream and downstream transit times
of the transducers. The Delta-T of fset sh ou ld normally be set
to zero.
Note: Consult GE Panametrics before performing this step.
a. Press [ENTER] to open the text box.
b. Use the numeric keys to enter the recommended value.
c. Press [ENTER] to confirm your entry.
3. The next prompt, the transmitter sample size, is t he number of
pulses each transmitter (upstream and downstream) emits. It is
set to 8 by default.
Note: Consult GE Panametrics before performing this step.
a. Press [ENTER] to open the drop-down list.
b. Use the [T] or [S] arrow keys to scroll to the
recommended number.
c. Press [ENTER] to confirm your selection.
4. The next prompt asks for the zero cutoff. Near “zero” flow,
the PT878GC may have fluctu ating 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:
a. Press [ENTER] to open the text box.
b. Use the numeric keys to enter the desired value.
c. Press [ENTER] to confirm your entry.