Teledyne 6000B Operating Instructions Manual page 46

3 Operation
and displays this difference as Slope on the screen. It takes several seconds for
the first Slope value to display. Slope indicates rate of change of the Span
reading. It is a sensitive indicator of stability.
When the Span value displayed on the screen is sufficiently stable, press
Enter. (Generally, when the Span reading changes by 1 % or less of the range
being calibrated for a period of ten minutes it is sufficiently stable.) Once Enter
is pressed, the Span reading changes to the correct value. The instrument then
automatically enters the Analyze function.
3.4.3 Offset Function
This software when installed in the 6000B instruments provides a way to enter
an offset on the zero operation of the analyser. This is useful when the instrument
is zeroed in some inert gas such as Nitrogen or Argon, but the background gas
of the process is different. If the background gas of the process is different than
the zero calibration gas being used, the reading will have an offset that will be
constant throughout its working range. Thus, the need to provide an offset when
the instrument is being zeroed.
How to access the offset function:
To access this function, the instrument zero mode must be entered by pushing the
Zero key on the front panel of the control unit. The VFD display will show the
following menu selection:
or
Select whether you want the instrument to do an automatic or manual zero. If
you do an automatic zero, the instrument does the zero by itself. If you do a
manual zero you must manually enter inputs to the instrument to accomplish the
zero, see in the corresponding section of the manual on how this two functions
differ.
When the Enter key is pressed, the following menu will appear:
3-20 Part I
####.##% SO2
Slope=#.### Span
Select zero
mode: AUTO
Select zero
mode: MAN
Zero off: 0.0 ppm
<ENT> to begin Zero
Teledyne Analytical Instruments
Model 6000