NuAire LabGard NU-813-300, Руководство по эксплуатации и техническому обслуживанию

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OM0236 Page 37 of 52
February/2019
813 Dual HEPA Filter Testing
The NU-813 (Series 30) with the double HEPA filter option requires additional HEPA filter integrity testing.
The additional HEPA filter integrity tests are performed by accessing the ports behind the control box.
THESE PORTS ARE UNDER POSITIVE PRESSURE,
SO ACCESS SHOULD ONLY BE MADE WITH THE BLOWER OFF.
The access port LABELED S is connected to a sample tube which runs between the two filters.
The purpose of this port is to measure the primary HEPA filter’s integrity with a photometer.
When using a photometer to gross leak test the primary HEPA filter, the leakage shall not exceed .005% of the upstream
concentration. A similar technique may be used for a particle counter using the applicable methods and techniques.
For the primary HEPA the P.A.O. challenge is introduced into the cabinet workzone and the sample probe is taken from the port
labeled S on the unit behind the control box.
P.A.O. challenge introduced into cabinet Gross leak sample taken from the primary HEPA filter
workzone center rear wall
P.A.O. challenge introduced Probing exhaust airstream
The secondary HEPA filter may also be gross leak tested using the secondary filter P.A.O. supply port LABELED C to supply a P.A.O.
challenge to the filter. An internal reference must be used instead of measuring upstream concentration. Normal gross leak testing
techniques may then be used to verify filter integrity of the secondary HEPA.
For the secondary HEPA the challenge is introduced into the port labeled C on the unit.
The probe sample is taken at the outlet of the unit along the protective screen
CAUTION
!