SKC 225-95 Series Gelatin Filters - Manual (Page 2)

Sampling Parameters
Max. sampling time: 30 minutes
Max. recommended air face velocity (through fi lter): 0.4 meters/second (m/sec)
Prolonged sampling time and high air velocity may destroy gelatin pores leading
to a decrease in collection effi
ciency of gelatin fi lters.
Note: Air velocities nearer 0.4 m/sec require shorter sampling times. Conversely, lower
air velocities allow longer sampling times.
Face velocity for specifi c samplers/fi lter diameters:
• IOM Sampler with 25-mm fi lter at 2 L/min fl ow rate = air face velocity of
0.08 m/sec
• Butt on Sampler with 25-mm fi lter at 4 L/min fl ow rate = air face velocity
of 0.16 m/sec
• 37-mm fi lter at:
 2 L/min fl ow rate = air face velocity of 0.035 m/sec
 4 L/min fl ow rate = air face velocity of 0.07 m/sec
 10 L/min fl ow rate = air face velocity of 0.17 m/sec
Operation
Filter Handling Guidelines
• Gelatin
fi lters are britt le; handle fi lters carefully.
• Do not touch fi lters with fi ngers or foreign objects.
• Use forceps to handle fi lters.
• Do not grip fi lters too tightly with forceps; this will cause breakage.
• Avoid
bending fi lters.
• Keep pocket on fi lter until ready to load into a cassett e. See Loading a Gelatin
Filter into a Cassett e.
Loading a Gelatin Filter into a Cassett e
Note: Load the fi lter only under sterile conditions. Follow Filter Handling Guidelines.
1. Disassemble the cassett e and carefully let the gelatin fi lter slide out of its
pocket into the cassett e.
2. Use forceps to aid in positioning the fi lter.
3. Reassemble the cassett e.
4. Use fl exible tubing to connect the outlet of the cassett e to the inlet of an
air sample pump capable of the desired fl ow rate.
5. Sample for the appropriate sampling period up to 30 minutes (see Sampling
Parameters). Sampling periods should be brief to help reduce microorganism
stress.
Handling and Shipping the Filter Aft er Sampling
Determine the method of analysis to be used, direct or indirect, before preparing
the sample for shipment. There are two methods for shipment preparation.
Method 1 can be used for shipping to a laboratory at a diff erent location.
Method 2 should only be used if there is an on-site laboratory that can perform
microbial analysis.