Teledyne 7120 - NDIR analyzer - Manual (Page 39)

4 Operation Model 7120
4-6 Teledyne Analytical Instruments
If you do not wish to continue a function, you can abort the session by
escaping . Escaping a function takes the analyzer back to the previous screen, or
to the ANALYZE Function, depending on the function escaped.
reproduced, at the appropriate point in the procedure, in a Mono-
spaced type style. Push-button names are printed in Oblique type.
4.3.2 Setting up an AUTO-CAL
When proper automatic valving is connected (see chapter 3, installation),
the Analyzer can cycle itself through a sequence of steps that automatically zero
and span the instrument.
Note: Before setting up an AUTO-CAL, be sure you understand the
Zero and Span functions as described in section 4.4, and
follow the precautions given there.
Note: If you require highly accurate AUTO-CAL timing, use external
AUTO-CAL control where possible. The internal clock in the
Model 7100 is accurate to 2-3 %. Accordingly, internally sched-
uled calibrations can vary 2-3 % per day.
Note: If your ranges are configured for different applications, then
AUTO-CAL will calibrate all of the ranges simultaneously (by
calibrating the Cal Range).
To setup an AUTO-CAL cycle:
The VFD will display five subfunctions.
Call out MAIN MENU, scroll to AUTO-CAL function, and ENTER. A
new screen for ZERO/SPAN set appears.
ZERO in Ød Øh off
SPAN in Ød Øh off
Use UP or DOWN key to blink ZERO (or SPAN ), then Enter. (You
won’t be able to set OFF to ON if a zero interval is entered.) A Span Every ...
(or Zero Every ...) screen appears.
Zero schedule: OFF
Day: Ød Hour: Øh
Use UP or DOWN key to set a value in days, then ENTER to move to the
start-time value in hours. Use UP or DOWN keys to set a start-time value, then
ENTER.
To turn ON the SPAN and/or ZERO cycles (to activate AUTO–CAL): useUP
or DOWN keys to set the OFF /ON field to ON. You can now turn these fields
ON because there is a nonzero span time defined.