Teledyne 3000TA-EU - General purpose trace oxygen analyzer User Manual
Page 57
Trace Oxygen Analyzer
Operation
Teledyne
Analytical
Instruments
45
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.
4.4.1.2
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
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.
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
C
ELL
F
AILURE
Cell failure in the 3000TA is usually associated with inability to
zero the instrument down to a satisfactorily low ppm reading. When this
occurs, the 3000TA system alarm trips, and the LCD displays a failure
message.