Method:
1. Lower the front window to a
height of 3 in. (7.6 cm).
2. Operate the system blowers for
approximately 20 minutes.
3. Insert the thermal anemometer
probe into the probe holder.
Place the probe holder at the
window opening work surface,
ensuring it is seated properly.
See Figure 8-1. Adjust the
probe so the air passing through
probe is centered in the window
opening (1.5 in. [3.8 cm]).
Note
The thermoanemometer
probe must be positioned at a 10°
angle from front vertical and
located on the same plane as the
inside of the window glass.
4. Beginning 3 inches in from the
left inside wall, record
successive readings every
5.9 inches (8 readings for 4 ft,
and 12 readings for 6 ft
models).
5. Average those readings and
correct result for true velocity.
6. Calculate the inflow velocity as
described below.
Calculation:
• Inflow velocity (V1) = average of actual inflow velocity * K factor * 0.3
for 10” window opening work position
K factor = 1.04 for 4 ft w/ 10” opening.
K factor = 1.067 for 6 ft w/ 10” opening.
Acceptance:
• 100 – 110 FPM
Refer to the data plate on the lower right corner of the unit face.
s
1500 Series A2 8-5
Thermo Scientific
Section 8
Certification Testing
Testing Information
(continued)
Figure 8-1.
Constricted Window Method
5.9”
3”
3”
1.5”
3”
