• 6ft Models (10” window opening work position) 1589,1579: Front opening
4.92 sq ft
Calculation:
• Average exhaust velocity (V2) = Sum of measurements / Number of
readings
• Exhaust Volume (V3) = Average velocity (V2) x Effective filter area (A3)
• Inflow velocity (V1) = Exhaust volume (V3) / Work opening area (A2)
Acceptance:
• 100 – 110 FPM
Downflow Velocity – Uniform Cabinet
Description:
• Measures the velocity of air flow onto the work surface through the
supply filter.
Equipment:
• Thermal Anemometer, or equivalent (hotwire)
• Freestanding Fixture, or equivalent
Method:
1. Operate the unit in the work position for approximately 20 minutes.
2. Insert the anemometer probe into the probe stand, adjusting for a
height of 4 inches (10 cm) above the bottom edge of the window
opening while in the work position.
3. Record the readings on a horizontal plane 4 inches (10 cm) above the
bottom edge of the window opening while in the work position, in a
grid pattern not to exceed 6 inches (15 cm) x 6 inches (15 cm).
Grid Pattern:
• 4 ft Models 1584,1574
1500 Series A2 8-7
Thermo Scientific
Section 8
Certification Testing
Testing Information
(continued)
6
5.5
5.5
6
6
3.9
3.9
3.9
3.9
3.9
3.9
6
inches
5.7 for
8 in
opening
models
21 points
