Teledyne 2000A-EU - General purpose thermal conductivity analyzer - Manual (Page 50)

4 Operation Model 2000A-EU
4-12 Teledyne Analytical Instruments
Note: Shut off the gas pressure before connecting it to the analyzer,
and be sure to limit pressure to 40 psig or less when turning it
back on.
Readjust the gas pressure into the analyzer until the flowrate through the
sensor settles between 50 to 200 cc/min (approximately 0.1 to 0.4 scfh).
4.4.1 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.
CAUTION: If you are zeroing the Cal Range by itself (multiple
application analyzers only), use manual mode
zeroing.
If you want to calibrate ALL of the ranges at once
(multiple application analyzers only), use
auto mode
zeroing in the Cal Range.
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.
4.4.1.1 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.
#### % O2 — N2
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 course 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.