2000 Fire Door-Fan Manual updated 2002-05-28 Page 24 of 58
Room and Flow Pressure Readings

Make sure the blower is running at half speed or more before taking any

readings.

Analog Gauge Readings
...from the Magnehelic gauges from the Model E Analog Gauge Clip
Tubing Connections:
For the 60-gauge- connect the red tube from the upper port through the panel. When the
blower is reversed, the red tube must be connected to the lower port.
For the 250-gauge, plug the clear tube from the lower gauge port into the blower.
Gauge Reading Rules
Ensure the gauges are zeroed.
Read the gauges very carefully! The 240 Pa marker is easy to misread. Please refer to
the diagram below for clarification.
Your eye must be perpendicular to the gauge faceplate to remove "parallax error".
Wait 15 to 20 seconds after the last speed control adjustment to let the readings
stabilize before writing down the test data or entering it directly into the computer.
(For optimum results tap the gauges lightly to remove hysterisis and get the most
accurate reading possible.) Take results from both Room Pressure and Flow Pressure
gauges simultaneously since they will sometimes move up and down together.
240 Pa marker
250 Pa marker
5 Pa division