Teledyne 3160 - Manual (Page 30)

4-2
4 Operations 4 Operations 4 Operations 4 Operations 4 Operations
TELEDYNE ANALYTICAL INSTRUMENTS
displaying the function of each button directly above it. The LCD screen displays the
current mode and any warning messages, instructions and button functions.
4.1.1 Spinning Wheel
A “spinning wheel” appears in the upper left-hand corner of the LCD display to
indicate that the alarms are enabled (any that are not defeated), or that scheduled zeroing
(AutoZeroing) or scheduled spanning (AutoSpanning) may take place. If the spinning
wheel does not appear, the alarms are disabled, and a scheduled zero or span is defeated.
Note that there is a delay of several minutes before the spinning wheel appears whenever
the Analyze mode is re-entered.
4.1.2 Cell Output Factor (Span Factor)
The expected life of the Micro-Fuel Cell sensor is about eight months. A guide to the
relative life left in the cell can be found on status page 2 (see System Statistics near the end
of this chapter) or retrieved from the serial port through the serial command SF. The span
factor ranges from 0.00 to 1.00, with 1.00 representing full life expectancy. A span factor
below 0.1 indicates that the Micro-Fuel Cell needs replacing.
4.2 Modes of Operation
To use the system and select displayed options, press the button directly underneath
the option you wish to select. There are eleven different menus:
Cold Start-Up: During the first startup, and when subsequent cold start-
ups are chosen by the user, initial values set at the factory for alarms, I/O,
calibration, zeroing and other data are used.
Upon cold start, zeroing and calibration should be performed before
accurate oxygen measurements are obtained. A system warm start is automati-
cally performed on each subsequent power-up. For a warm start, previous
user-input configuration data is preserved in RAM by battery-preserved
memory in the system control module.
Calibration Zeroing: For the highest possible accuracy, the analyzer
must be zeroed using an oxygen-free gas. By eliminating normal background
“noise” from the sensor reading, zeroing resets the level referred to as the
“zero” oxygen concentration.
If the analyzer is equipped with a scrubber, it is important to zero the
analyzer with a near-zero gas connected to the sample port. The zeroing
process automatically opens pneumatic valves on either side of the scrubber,
and a gas with a high concentration of oxygen will react with the scrubber and
necessitate replacement sooner.