April 2004
9-18 Servicing the PT878GC
Programming the Thickness Gauge (cont.)
1. Press the [T] arrow key to enter the window.
2. The first prompt asks for the low signal threshold. If the signal
strength falls below this value, a “Low Signal” message
appears on the screen. To change this value:
a. Press [ENTER] to open the text box.
b. Use the numeric keys to enter the provided value.
c. Press [ENTER] to confirm your entry.
3. The next value, transducer delay, represents the time the
ultrasonic signal takes to travel from the meter to the pipe
material surface. To change this value:
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.
4. The signal inversion prompt enables you to invert the
thickness transducer signal. Signal inversion may be
necessary if your thickness readings show unusual jitter , or for
certain unusual combinations of pi pe and fluid or pipe and
lining. Consult the factory before measuring the thickness of
lined pipes.
Note: When measuring the thickness of certain pipe materials,
you might need to drain the pipe before mea suring the
pipe wall, because certain pipe/liquid combinations
muffle the ultrasonic echo.
Signal inversion should be on, unless you have received other
instructions. To change its status, use the [W ] and [X] arrow
keys to move to the appropriate radio button and press [ENTER].
5. To enter the noise threshold:
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.