1. DG-1000:
Select Flow (CFM) from the Mode menu. Touch Device to open the Device menu and select Exhaust Fan
Flow Meter. Touch Configuration to open the Configuration menu and select which door position is being used. Touch
the arrow in the upper left of the screen to return to the Gauge app screen.
DG-700:
Press the Mode button twice to put the gauge in PR/FL mode. Press the Device button until EXH appears in
the device section of the display. Press the Config button until the setting on the gauge matches the door position on
the metering box.
2. With the exhaust fan turned on, place the Exhaust Fan Flow Meter completely over the fan grill so that the flexible
gasket on the end of the metering box creates an air tight seal around the grill. Hold the gauge steady for at least 10
seconds so that the gauge auto-zeros.
3. Acceptable metering box pressures
• When using the Exhaust Fan Flow Meter, the measured metering box pressure should never be greater than 8.0
Pa, and never lower than 1.0 Pa. Pressures above 8.0 Pa will commonly result in erroneous flow measurements
because the metering box will tend to restrict air flow through typical residential exhaust fans. Metering box
pressures below 1.0 Pa are too small to measure accurately.
4. Channel A pressure greater than 8.0
• If the Channel A pressure is above 8.0 Pa, first check the door position. If the door position is set to E2 or E3,
adjust the position to create a larger opening in the metering box (e.g. E1 or E2). If the door position is set to
E1 (the largest opening) and the metering box pressure is still above 8.0 Pa, then the fan flow you are trying to
measure is outside the high range of the instrument (i.e. flow is greater than 124 CFM).
Flow (CFM)
Exhaust Fan Flow Meter
Door position
