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Teledyne 3000TB-XL - Trace oxygen analyzer User Manual

Page 68

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5 Maintenance

Model 3000TB

­XL

5-6

Teledyne Analytical Instruments

5.3.4 Installing a New Micro-Fuel Cell

It is important to minimize the amount of time that a Teledyne Trace Oxygen

Sensor is exposed to air during the installation process. The quicker the sensor
can be installed into the unit, the faster your TAI O

2

sensor will recover to low O

2

measurement levels.

CAUTION: Do not touch the sensing surface of the cell. It is cov-

ered with a delicate Teflon membrane that can leak when
punctured. The sensor must be replaced if the mem-
brane is damaged.

Before installing a new cell, check the O-ring in the base of the cell holder.

Replace if worn or damaged.

Place the cell on the holder with the screen side facing down.

Note: There is a small location hole drilled in the holder. This hole mates

with a guide pin on the bottom rear of the cell block. The hole in
the cell block holder must align with the guide pin on the cell block.

Step 1. Remove power from instrument.

Step 2. Remove the old sensor (if installed) from the analyzer.

Step 3. Purge the analyzer at approximately 1 SCFH flow rate with

N

2

(or applicable sample gas with the sensor holder re-

moved).

Step 4. Remove sensor from double bag storage.

Step 5. Remove sensor shorting button.

Step 6. Place sensor on sensor holder so that the gold contact plate of

the sensor is facing up towards the sky.

Step 7. Install sensor and sensor holder into cell block.

Step 8. With O-ring in place, align the guide pin with the hole on the

cell holder. Then, with the holder, lift cell into the cell block.

Step 9. Push the gate on the cell block down so that the slots on the

side of the gate engage the locating screws on the side of the
block. This forces the holder into position and forms a gas-
tight seal.

Step 10. Purge system with sample or zero gas.

Step 11. Power-up.

If steps 4 through 10 are accomplished quickly (elapsed time less than 15
seconds), recovery to less than 1ppm level should occur in less than 8 hours.