Page 7-2
MiniCapt Remote Microbial Air Sampler Operations Manual
Chapter 7 Maintenance and Performance Checks
Performance Checks
Performance Checks
Complete the following procedures to verify that your instrument is operating properly.
Airflow Rate Check
The sample flow is factory-set using a critical orifice and is not adjustable. If the flow
drops by 15% there may be a blockage in the critical orifice or inlet jet.
A flow meter with suitable range for the instrument type (25, 50, or 100 LPM) is required.
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To check the air flow rate:
1
Disconnect all sample tubing and sample probes.
2
Connect the unrestricted test flow meter to the sample inlet fitting.
3
Run a sample and monitor the flow meter readings.
The measured flow should be the following:
• 25 LPM + 5%
• 50 LPM + 5%
• 100 LPM + 5%
A flow rate error greater than ±5% results in sample warnings.
A flow rate error greater than ±20% results in an alarm.
Low flow could be due to a blockage.
