Table of Contents
Advertisement
4 Operation
4.8.1.3
Cell failure in the 3020T is usually associated with inability to zero the
instrument down to a satisfactorily low ppm reading. When this occurs, the
3020T system alarm trips, and the VFD displays a failure message.
Before replacing the cell:
a. Check for leaks downstream from the cell, where oxygen may be
leaking into the system.
b. Check your span gas to make sure it is within specifications.
c. If there are no leaks and the span gas is OK, replace the cell as
described in chapter 5, Maintenance.
d. After correcting the condition, reset the Cell Fail Alarm by taking
the analyzer into, and then back out of, STANDBY.
4.8.2 Span Cal
SPAN is used to span calibrate the analyzer. Span calibration can be
performed using the automatic mode, where an internal algorithm compares
consecutive readings from the sensor to determine when the output matches
the span gas concentration. Span calibration can also be performed in
manual mode, where the operator determines when the span concentration
reading is acceptable and manually exits the function.
4.8.2.1
Scroll to SPAN, and ENTER the SPAN function. The screen that
appears allows you to select whether the span calibration is to be performed
automatically or manually. Use the DOWN/UP control to toggle between
and
span settling. Stop when
Use ENTER to move to the next screen.
Use DOWN/UP to start changing the oxygen-concentration. Use
ESCAPE/ENTER to blink the digit you are going to modify. Use DOWN/UP
again to change the value of the selected digit. When you have finished
4-12
Cell Failure
Auto Mode Spanning
Teledyne Analytical Instruments
appears on the display.
Model 3020T
Advertisement
Table of Contents
