Teledyne 5000B - Near Infrared Photometer User Manual
Page 48
3 Operation
/Control Unit
Model 5000B
3-20 Part I
Teledyne Analytical Instruments
Use the DÑ keys to toggle between AUTO and MAN span settling. Stop
when MAN appears, blinking, on the display. Press Enter to move to the next
screen.
Span Val: 2Ш.ШШ %
Use the < > arrow keys to toggle between the span concentration value
and the units field (%/ppm). Use the DÑ arrow keys change the value and/
or the units, as necessary. When you have set the concentration of the span
fluid you are using, press Enter to begin the Span calibration.
Press Enter to enter the span value into the system and begin the span
calibration.
Once the span has begun, the microprocessor samples the output at a
predetermined rate. It calculates the difference between successive samplings
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.
####.##% SO2
Slope=#.### Span
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 5000BF 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 fluid such as Nitrogen or Argon, but the
background fluid of the process is different. If the background fluid of the
process is different than the zero calibration fluid 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: