Percent Paramagnetic Oxygen Analyzer
Part I: Control Unit
Part I: 4-13
Teledyne Analytical Instruments
4.4.1.2
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
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 prede-
termined 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
Slope
Slope
Slope
Slope
value to display.
Wait about 10 seconds. Then, wait until
Slope
Slope
Slope
Slope
Slope
is sufficiently
close to zero before pressing
Enter to finish zeroing.
Slope
Slope
Slope
Slope
Slope
is
given in ppm/s.
Generally, you have a good zero when
Slope
is less than 0.05 ppm/s
for about 30 seconds. When
Slope
is close enough to zero, press
Enter
. In a
few seconds, the screen will update.
Once span settling completes, the information is stored in the
microprocessor, and the instrument automatically returns to the
Analyze
mode.
4.4.1.3
Cell Failure
Cell failure in the 3010MB is usually associated with inability to zero
the instrument down to a satisfactorily low ppm reading, e.g. cell does not
fail if it comes below 5PPM . When this occurs, the 3010MB system alarm
trips, and the LCD displays a failure message.
#.# ppm Anlz
CELL FAIL/ ZERO HIGH
Before replacing the cell:
a. Check your span gas to make sure it is within specifications.
b. Check for leaks downstream from the cell, where oxygen may be
leaking into the system.
