Hach Met One 6000 Series, User Manual, Page: 46 / 70

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Maintenance
5.2.3 Purging
Purging is an extension of zero counting ( section 5.2.2 ), running as long as is necessary
to achieve zero count results, often for 24 hours. Purging is usually done before a test to
make sure there is a proper baseline reference for the counter.
1. Cut off approximately one inch of the inlet tubing so that any stretched or scored
section is removed for a good seal.
2. Attach a standard purge filter assembly to the sensor inlet tube.
3. Allow the counter to operate for 24 hours. If a zero count is not reached after 24
hours, inspect the sample tubing for contamination and change if necessary.
For further help, contact an authorized service center for Hach Company.
5.3 Tubing replacement
The inlet tubing (from the counter to the isokinetic probe) should be replaced regularly to
avoid organic growth or inorganic particle contamination on the tube walls. Such
contamination may result in false high particle counts. Tubing of typical FMS installations
in life science and pharmaceutical manufacturing cleanrooms are recommended for
replacement once every year.
5.4 Calibration
The Met One 6000 particle counter must be returned to the service center for calibration
(refer to
Return procedures on page 49 ). Long-term instrument service contracts are
available from Hach Company. Contact the nearest Hach Company sales or service
representative for more information.