Installation Instructions 
Document No. 129-095 
September 24, 2009 
 
QVM62.1 Air Velocity Sensor 
 
 
Item Number 129-095, Rev. AA  Page 1 of 3 
Product Description 
This sensor is used to measure the air velocity in a 
duct and provide a 0 to 10V signal to a controller 
that is proportional to the velocity. This allows the 
controller to maintain a constant airflow in the duct, 
balance out pressure fluctuations (supply or exhaust 
air control), or just monitor the flow in a duct. The Air 
Velocity Sensor is generally used for modulating fan 
control in primary applications to set the basic 
volume flow. 
Product Number 
QVM62.1 
Warning/Caution Notations 
WARNING: 
Personal injury/loss of life may 
occur if you do not follow the 
CAUTION: 
Equipment damage or loss of 
data may occur if you do not 
follow the procedures as 
Required Tools 
•  Pencil 
•  Hammer 
•  Center hole punch 
•  Screwdrivers 
•  Four - #8 × 1/2-inch sheet metal screws 
•  Electric drill with 1/8-inch and 7/8-inch  
drill bits 
Expected Installation Time 
45 minutes 
Prerequisites 
Field wiring must be pulled to installation location. 
Installation 
Probe Mounting Flange and Sensor 
1.  Determine the depth of insertion required for 
the probe and assemble the extension tube 
and/or probe end cap onto the primary sensor 
head tube.  
NOTE:  If the insertion depth required is less 
than or equal to 5.7 inches (145 mm) 
the extension tube may be removed by 
disconnecting the probe cable at the 
transducer head, and sliding the 
extension tube off the cable. (With the 
extension tube installed, the probe’s 
depth of insertion is 11.8 inches 
[300mm].) If the extension tube is 
removed, be sure to reinstall the 
probe’s end cap on the cable before 
rewiring it to the transducer head. 
2.  Position the probe mounting flange on the duct 
where will be installed. Lightly tap the screw 
heads to create drill marks for the mounting 
screw holes. 
NOTE:  Install the sensor in the ductwork in a 
location where the airflow is not 
turbulent. Do not place it close to 
dampers, registers, or bends in 
ductwork. 
 
 
Figure 1.  Mounting Locations.