Teledyne 6000A - Photometric analyzer - Manual (Page 40)

3 Operation Model 6000A
3-16 Part I
Teledyne Analytical Instruments
Readjust the gas pressure into the analyzer until the flowrate through the
Sample Cell settles between 50 to 200 cc/min (approximately 0.1 to 0.4
SCFH).
Note: Always keep the calibration gas flow as close to the flowrate of
the sample gas as possible
3.4.1 Zero Cal
The Zero button on the front panel is used to enter the zero calibration
function. Zero calibration can be performed in either the automatic or manual
mode.
Make sure the zero gas is flowing to the instrument. If you get a
CELL
CANNOT BE BALANCED message while zeroing skip to section 4.4.1.3.
3.4.1.1 Auto Mode Zeroing
Observe the precautions in sections 4.4 and 4.4.1, above. Press Zero to
enter the zero function mode. The screen allows you to select whether the zero
calibration is to be performed automatically or manually. Use the
∆∇ arrow
keys to toggle between
AUTO and MAN zero settling. Stop when AUTO appears,
blinking, on the display.
Select zero
mode: AUTO
Press Enter to begin zeroing.
####.## % SO2
Slope=#.### C—Zero
The beginning zero level is shown in the upper left corner of the display. As
the zero reading settles, the screen displays and updates information on
Slope=
in percent/second (unless the Slope starts within the acceptable zero range and
does not need to settle further). The system first does a coarse zero, shown in
the lower right corner of the screen as
C—Zero, for 3 min, and then does a fine
zero, and displays
F—Zero, for 3 min.
Then, and whenever Slope is less than 0.01 for at least 3 min, instead of
Slope you will see a countdown:
9 Left, 8 Left, and so fourth. These are software
steps in the zeroing process that the system must complete, AFTER settling,
before it can go back to
Analyze . Software zero is indicated by
S–Zero in the
lower right corner.