Casella Evolution CM2010 Посібник з експлуатації - Сторінка 10

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EVOLUTION SERIES CM2010 OZONE ANALYSER

Check Zero Air Scrubber

The zero air supply is critical to the operation of the CM2010 analyser and the IZS module. Poor zero

air can result in numerous problems (for example, inaccurate measurements near zero and span drift).

Check the quality of the zero air system by challenging the analyser with a known good zero air source

(such as commercially available Ultra Zero Air) or a known good charcoal scrubber. To check the zero

air system, perform the following procedure.

Required Equipment:

1. From the CALIBRATION MENU, put the analyser in CAL. MODE: ZERO. This allows the ana-

lyser to sample zero air from the zero air scrubber. Allow the analyser to sample for

approximately 15 minutes.

2. Record the front panel O

3. Connect the challenge zero air to the Sample inlet of the analyser. Be sure the inlet pressure is

maintained at ambient pressure.

4. From the CALIBRATION MENU, select CAL. MODE: MEASURE and press the <Enter> key.

This allows the analyser to sample the challenge zero air. Allow the analyser to sample for

15 minutes.

5. Record the front panel O

6. Compare the initial O

the initial value is more positive than the challenge value, recharge or replace the zero air

scrubber.

7. Disconnect the challenge zero air and reconnect the sample line to the Sample inlet of the ana-

lyser. Verify that the analyser is in the Sample Measure mode.

The life span of a zero air scrubber typically depends on the amount of pollutant it is required to scrub.

Closely monitor the performance of the zero air system after initial installation and note when the zero

air begins to degrade. This interval can be used as the baseline for establishing a zero air maintenance

schedule.

Average Ambient O

0 to 30 ppb

30 to 100 ppb

> 100 ppb

Charcoal Replacement

1. Turn the analyser pump off.

2. Disconnect the pneumatic fitting from the top of the scrubber and DFU. Loosen the Velcro strap

securing the scrubber and remove the scrubber from the analyser.

3. Unscrew the scrubber cap and remove the plastic insert, metal screen, and felt pad. Pour the

charcoal out of the scrubber and refill with fresh charcoal.

4. Replace the felt pad, metal screen, plastic insert, and canister lid.

Test zero air supply

reading as the initial value.

reading as the challenge value.

value and the challenge value. They should agree within 0.002 PPM. If

Table 3-2 Charcoal replacement schedule

Concentration

Charcoal Replacement Interval

12 Months

6 Months

1 Month

HB4014-02