TSI Incorporated PORTACOUNT PRO+ 8038, Руководство по эксплуатации и обслуживанию

Страница: 38 / 107

32 Chapter 4
be measured otherwise. The risk is that you may fail people who
have good fits, thereby wasting time and effort. There is no
possibility that failing the Zero Check could result in overstated fit
factors. This is because any particles leaking into the PortaCount
Pro fit tester are interpreted as mask leakage, resulting in lower fit
factors.
9. The Max Fit Factor Check is after the Zero Check. This check
determines if the PortaCount Pro is capable of measuring high fit
factors and if the internal switching valve is functioning properly.
The test is essentially a fit test on a HEPA filter which simulates a
perfectly fitting respirator. A very high fit factor should result if the
instrument is working properly. The Max FF Check actually
measures the maximum fit factor that can be determined by the
PortaCount Pro fit tester given the local ambient particle
concentration and the mask sample time programmed into the
PortaCount Pro fit tester. Assuming the Zero Check Filter is
perfect, the maximum fit factor will be the local ambient particle
concentration divided by a mask concentration equivalent to one
particle during the mask sample time. When the PortaCount Pro
fit tester actually measures zero particles during the mask
sample, one particle is artificially added to prevent division by
zero when calculating the fit factor. Performing this test is futile if
there are leaks in the system. If this test fails refer to the
Troubleshooting chapter.
10. Press EXIT when the tests are complete. If the PortaCount Pro fit
tester passed all tests, proceed to Step 4
– Conducting Fit Tests
.
If the instrument failed any test, refer to the Troubleshooting
chapter to resolve the problem and then run the Daily Checks
again.
Step 4
—Conducting Fit Tests
1. Make sure the instrument is turned on, and the database you
want to work with has been selected (in order to save fit test
results and other information).
2. Instruct the person being tested to put on the respirator 5 minutes
before the fit test starts to purge the particles trapped inside the
respirator and permit the wearer to make certain the respirator is
comfortable. Have the subject don the mask
without assistance .
Fit test results depend on the subject knowing how to properly
don the mask. Train all subjects in proper mask-donning
techniques before being fit tested. Do
not allow the subject to
adjust the mask during the exercises, as this invalidates previous
results.