A-8
Appendix Model 3000PA
Teledyne Analytical Instruments
A-6 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. In the automatic mode, an internal algorithm compares consecutive
readings from the sensor to determine when the output is within the accept-
able range for zero. In the manual mode, the operator determines when the
reading is within the acceptable range for zero. Make sure the zero gas is
connected to the instrument. If zeroing is becoming more and more dificult,
skip to section 4.4.1.3 Cell Failure.
Auto Mode Zeroing
Press
Zero
to enter the zero function mode. The screen allows you to
select whether the zero calibration is to be performed automatically or manu-
ally. Use the ∆∇ arrow keys to toggle between AUTO and MAN zero
settling. Stop when AUTO appears, blinking, on the display.
Zero: Settling: AUTO
<ENT> To Begin
Press
Enter
to begin zeroing.
#### % Zero
Slope=#### ppm/s
The beginning zero level is shown in the upper left corner of the dis-
play. As the zero reading settles, the screen displays and updates information
on Slope (unless the Slope starts within the acceptable zero range and does
not need to settle further).
Then, and whenever Slope is less than 0.08 for at least 3 minutes,
instead of Slope you will see a countdown: 5 Left, 4 Left, and so fourth.
These are five steps in the zeroing process that the system must complete,
AFTER settling, before it can go back to
Analyze
.
#### % Zero
4 Left=### ppm/s
The zeroing process will automatically conclude when the output is
within the acceptable range for a good zero. Then the analyzer automatically
returns to the
Analyze
mode.
Manual Mode Zeroing
Press
Zero
to enter the
Zero
function. The screen that appears allows
you to select between automatic or manual zero calibration. Use the ∆∇ keys