Teledyne instruction manual Maintenance 319R, Replacing the Sensor

3.0 Maintenance 319R

5.Replace the fuse holder into its receptacle, pushing in firmly until it clicks.

In units with DC power, the fuse is located on the rear panel above the ON/OFF switch. Open the fuse holder by unscrewing and removing the knob marked FUSE. The fuse will be located inside the knob.

Replacing the Sensor

The characteristics of the Micro-Fuel Cell are similar to those of a mercury battery in that both provide an almost constant output through their useful life, and then fall off sharply towards zero at the end. If the sample being analyzed has a low oxygen concentration, cell failure will probably be indicated by the inability to properly calibrate the analyzer.

You will find that very little adjustment of the span potentiometer will be required to keep the analyzer calibrated properly during the duration of a given cell’s useful life. If large or many turn adjustments (clockwise) are required to calibrate the instrument, or calibration cannot be achieved within the range of the control, the cell needs replacing. Read the following section (Cell Warranty) before replacing the cell. Cell installation instruc- tions are in Chapter 2: Cell Installation.

In addition, if the LCD displays “00.0” when the unit is plugged in, and the power switch is in the ON position, the sensor needs to be re- placed.

IMPORTANT: After replacing the Micro-Fuel Cell, proceed to Chapter 2: Calibration.

To offset the possibility of not having a replacement cell available when needed, a spare cell can be ordered shortly after the instrument is in service, and each time after cell replacement thereafter.

NOTE: Do not stockpile cells, as the cell warranty begins on date of shipment.

Only one cell per instrument should be in reserve. The spare cell should be carefully stored in an area not subject to large variations in ambient temperature (75° F nominal), and in such a way to eliminate any possibility of damage. Under no circumstance should you disturb the integrity of the cell package until the cell is to be used. If the cell package is punctured and air permitted to enter, the cell will immediately start to react to the presence of oxygen.

10 TELEDYNE BROWN ENGINEERING

Analytical Instruments