Calculating the upstream concentration – Labconco PURICARE Procedure Station Models 34812xx User Manual
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Page 86 of 197
2. Locate the access tube on right side of the rear plenum wall, passing through the
towel catch. As shown in Figure 6-2.
Figure 6-2
3. Pull the tube toward the front of the unit. Remove the access tube cover.
4. Using an appropriate photometer, connect the unit's upstream line to the access
tube.
Note: Keep the photometer sampling tube as short as possible. It should
never exceed 6 feet maximum.
5. Turn on the photometer and allow it to operate for a minimum of 5 minutes.
Leave the valve in the “CLEAR” setting.
6. Check the oil level of the generator – it must be within 1/8” of the level line
when the generator is sitting level.
Calculating the upstream concentration
If you do not want to connect the upstream line of the photometer to the sampling port
located on the supply filter plenum, you must calculate the upstream concentration.
Testing at Labconco has shown the actual concentration varies from the calculated
value. Table 6-1 shows the actual vs. calculated concentrations for the B2 models.
Table 6-1
Supply HEPA Filter Leak Test Specifications
Model 34410
34610
Air Displacement (CFM)
445
665
Laskin Nozzles needed
1
1
Theoretical aerosol conc.
(ug/l)
1
30 20
Actual aerosol conc. (ug/l)
1
15
12
Nominal Speed Control
Setting
74 73
1. The calculated concentration was established by the formula:
Concentration (ug/l) = (# Laskin nozzles @ 20 PSIG x 13,500)/Volume of air displaced
2. Based on Mineral oil