Panametrics DigitalFlow GC868, Service Manual, Page: 30 / 64

Chapter 3. Diagnostics
3-1 DigitalFlow™ GC868 Service Manual (1 and 2-Channel)
3.1 Introduction
This chapter explains how to troubleshoot the Model GC868 if problems arise with
the electronics console, the flowcell, or the transducers. Indications of a possible
problem include:
• display of an error message on the active display screen
• erratic flow readings
• readings of doubtful accuracy (i.e., readings that are not consistent with
readings from another flow measuring device connected to the same process).
If any of the above conditions occurs, proceed with the instructions presented in this
chapter.
3.2 Displaying
Diagnostic
Parameters
The Model GC868 has a built-in
Diagnostics Menu
to aid in the troubleshooting of
flowcell, transducer and/or electrical problems. The Diagnostics Menu may only be
entered from the Big or Dual measurement mode display. See Chapter 2, Displaying
Data,
in the
Programming Manual
for instructions on setting the display screen to the
desired format, and enter the Diagnostics Menu as shown below.
1. For a 2-channel GC868, press the [
←
] or [
→
] keys until the desired channel
option appears on the option bar. Press the appropriate [Fx] key to select this
option.
Note:
For a 1-Channel Model GC868, the above prompt does not appear, and the
following prompt is the initial screen.
2. Press the [
←
] or [
→
] keys until DIAG appears on the option bar. Press the
appropriate [Fx] key to select this option.
Note: Ch1 (or Ch2), which is shown in parentheses above, appears in the locator
bar only with a 2-Channel Model GC868.
For example, pressing [F1] displays the Tdown parameter, as shown in the following
prompt.
Ch1 label gSITE
Press the [
←
] and [
→
] keys
and the appropriate [Fx] key
to display a different
diagnostic parameter or to
EXIT the Diagnostics Menu .
Ch1 DN Transit usec
519.7
(error codes appear here)
Tdown DELTA PEAK% Qup