Faster ASEPTIC, Руководство по эксплуатации и техническому обслуживанию

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00254EN – Rev. 01 – 11/2012 40
13 TESTS PERFORMED ACCORDING TO EN 14644-3 STANDARD
13.A MEASUREMENT OF LAMINAR AIRFLOW VELOCITY
The LAF velocity is measured at 250 mm under the HEPA filter taking the reading in at least 8 points:
In our tests the readings are taken in 12 points as above-diagrammed. Each one of the 12 readings lasts at
least 1 minute. The velocity is measured with a hot-wire thermo anemometer with the following features:
Measure-Range
0
÷
2 m/s
Precision (of the device including the probe) +/- 0.05 m/s +/- 5%
Working temperature From – 20 to + 70°C.
Resolution
m/s
The average velocity is obtained by the following formula:
Average velocity = (V
1
+ V
2
+…+V
n
) / n
n = number of readings points
V
1
, V
2
…V
n
= velocities measured in the various points.
The average velocity must be 0.45 m/s
Ensure that no single measurement differs from the average of all the measures by +/- 20 %.