Teledyne 3300ZB - Low-cost Zirconium Oxide Oxygen Analyzer - Manual (Page 32)

Maintenance Model 3300ZB
Teledyne Analytical Instruments 22
To open the spare fuse compartment, push on one end until it
slides out.
4. Remove the bad fuse and replace it with a 5
20 mm 0.5 A,
250 VAC, IEC, time lag (T) fuse (P/N F1128) for AC units.
5. Replace the fuse holder into its receptacle, pushing in firmly
until it clicks.
5.2 Sensor Installation or Replacement
5.2.1 When to Replace a Sensor
The sensors used in this product will typically last five years or
longer in service. Typically, the sensors will fail either high or low.
Inaccurate or erratic readings are a sign that one of the sensors may have
failed. In most cases, we recommend the entire unit be returned to an
authorized Teledyne Service Center for sensor replacement.
To replace the sensor, refer to Figures 5-2 and 5-3 and follow the
procedure below:
1. If required, purge the lines with nitrogen to remove any toxic or
combustible gas from the cell.
2. Remove power from the instrument. Wait at least 1/2 hour to
allow the sensor to cool.
3. Unscrew the collar to separate the sensor cap from the sensor
block. See Figure 5-3 (A).
4. Carefully lift up the ZrO
2
sensor off the PCB and replace with a
new sensor. Align the tab of the sensor with the tab shown on the
silkscreen of the sensor PCB as shown in the inset of Figure 5-3
(B). Make sure the pins on the sensor mate properly with the
sockets on the PCB. Without touching the membrane surface,
push the sensor down until the pins seat in the sockets.
5. Replace the cap and screw the collar onto the block threads.
6. Apply power to the analyzer and flush the sensor block with
nitrogen for 20 minutes to remove trapped air.