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Retrotec DucTester 341 User Manual

Page 56

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Page 56 of 83
©Retrotec Inc. 2014

Adjust the

[Set Speed]

until Channel A reads a pressure of 0 Pa. Record the flow in CFM. To have the

DucTester automatically acquire and maintain a 0 pressure, press

[Set Pressure]

[0]

[Set] and the gauge

will cause the DucTester to increase in speed to eliminate whatever pressure it sees at the time that the
keys are pressed.

Ensure the pressure that is to be set to 0 actually exists before the keys are pressed because it uses the
direction of the pressure to set the direction of control. This means that the will fan speed up to
eliminate the pressure it first sees regardless of sign. Make sure the “@ Pressure” feature is turned off,
otherwise erroneous results will occur due to the result being divided by whatever tiny pressure occurs
above or below zero.

Optional

Sierra Building
Science device
for measuring
air handler
flow using a
blower door
connected with
flex to a return.