Teledyne 3020T - Manual (Page 41)

Trace Oxygen Analyzer Operation 4
4-5 Teledyne Analytical Instruments
4.3 The AUTO-CAL Function
When proper automatic valving is connected (see chapter 3, installa-
tion), the Analyzer can cycle itself through a sequence of steps that automati-
cally zero and span the instrument.
Note: If you require highly accurate AUTO-CAL timing, use external
AUTO-CAL control where possible. The internal clock in the
Model 3020T is accurate to 2-3 %. Accordingly, internally
scheduled calibrations can vary 2-3 % per day.
To setup an AUTO-CAL cycle:
Scroll to AUTO-CAL , and ENTER. A new screen for
Span/Zero set
appears.
Span OFF Nxt: 0d 0h
Zero OFF Nxt: 0d 0h
If SPAN (or ZERO ) is not between the arrows, scroll with DOWN/UP
control to SPAN (or ZERO ), 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.
Span Every 0 d
Start 0 h from now
Use DOWN/UP control to set an interval value, and ENTER. Then use
DOWN/UP to set a start-time value, and ENTER.
To turn
ON the Span and/or Zero cycles (to activate
AUTO-CAL ):
Scroll to
Auto—Cal,
and ENTER it again.
Span OFF Nxt: 0d 0h
Zero OFF Nxt: 0d 0h
When the
Span/Zero values screen appears, use the scroll DOWN to
blink the
OFF/ON field of the
SPAN (or ZERO ) function. Use DOWN/UP
to set the
OFF/ON field to ON. You can now turn these fields ON
because
there is a nonzero span interval defined.
4.4 The PWD (Password) Function
Security can be established by choosing a 5 digit password from the
standard ASCII character set. If you decide NOT to employ password
security, use the default password
TETAI. This password will be displayed
automatically by the microprocessor. The operator just ENTERs it to be
allowed total access to the instrument’s features.