User Manual

45170 V1.1 5/09
4
Data Hold
Press the HOLD button to freeze the reading in the display. The 'HOLD' icon will appear on
the upper right-hand side of the display. Press the HOLD button again to return to normal
operation (the 'HOLD' hold icon will disappear).
Auto Power OFF
The meter will automatically turn off after 10 minutes if no keys are pressed during this
period. Auto power off is disabled in the max/min recording mode.
Turning Power OFF
Press the power button to turn power off.
Calibration and Repair Services
Extech offers repair and calibration services for the products we sell. Extech also
provides NIST certification for most products. Call the Customer Care Department for
information on calibration services available for this product. Extech recommends that
annual calibrations be performed to verify meter performance and accuracy.
Useful Equations
Area equations
Cubic equations
CFM (ft
3
/min) = Air Velocity (ft/min) x Area (ft
2
)
CMM (m
3
/min) = Air Velocity (m/sec) x Area (m
2
) x 60
A = pi x R
2
R
A = W x H
W
H