Hach Ultra MET ONE HHPC-2, Руководство пользователя, Страница: 22 / 42

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Operation
4.6 Counter operation
Once the MET ONE HHPC–2 unit configuration is set:
• Use the zero count to verify the operation of the filter.
• Collect air samples, transfer them to a computer for further analysis and print them.
• Review the number of samples in the print buffer and, if needed, clear the print buffer.
4.6.1 Verify the MET ONE HHPC–2 with a zero count filter
Make sure that the instrument is not falsely counting due to sensor leakage, internal or
external electrical interference or any other reason before the unit is used for monitoring
or verifying clean-room condition.
Clean the MET ONE HHPC–2 using the zero count filter before storage or shipment.
Purge the MET ONE HHPC–2 with a zero count filter before using it in a clean-room or a
clean manufacturing environment. This process meets the Japanese Industrial Standard
B9221-1997 (JIS).
To verify the unit with a zero count filter:
1. Remove the isokinetic probe from the unit.
2. Attach the intake hose barb (MP000026-01).
3. Secure the high purity tubing (VP 792002) to the hose barb.
4. Secure the opposite end of the tubing to the zero count filter (VP212808). Make sure
the arrow on the filter is pointing away from the tubing. Now the unit is ready to purge
and zero count.
5. Operate the unit for approximately 15 minutes.
6. Verify that the data on the display is:
• Not more than one particle greater than 0.3
µ
m in five minutes on average, or
• Not more than one particle per 0.5 cubic foot.
Note: Initial counts are typically from particles shedding from components used for zero
counting. The zero count process or guidelines set forth by applicable industry standard(s) is
continued.
7. Remove the zero count filter and attach the isokinetic probe to resume normal
operations.
Figure 11 Program contrast screen