
Operation Model
3020T
Teledyne
Analytical
Instruments
44
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 forth.
These are five steps in the zeroing process that the system must
complete, AFTER settling, before it can go back to
Analyze
.
#### PPM
Zero
1 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.
4.8.1.2
M
ANUAL
M
ODE
Z
EROING
Press
Zero
to enter the
Zero
function. The screen that appears
allows you to select between automatic or manual zero calibration. Use
the
▲
/
▼
keys to toggle between
AUTO
and
MAN
zero settling. Stop
when
MAN
appears, blinking, on the display.
Zero: Settling: Man
<ENT> To Begin
Press
Enter
to begin the zero calibration. After a few seconds the
first of five zeroing screens appears. The number in the upper left hand
corner is the first-stage zero offset. The microprocessor samples the
output at a predetermined rate. It calculates the differences between
successive samplings and displays the rate of change as
Slope=
a value
in parts per million per second (ppm/s).
#### ppm
Zero
Slope=#### ppm/s
Note: It takes several seconds for the true Slope value to display.
Wait about 10 seconds. Then, wait until Slope is
sufficiently close to zero before pressing Enter to finish
zeroing.