user manual

407113-EN v3.4 10/13
7
Battery Replacement
When the LBT icon appears on the LCD, the 9V battery must be replaced.
1. Remove the rubber holster that surrounds the entire meter
2. Slide off the rear battery compartment
3. Replace the 9V battery
4. Affix the battery compartment cover and the meter holster
Useful Equations and Conversions
Area equation for rectangular or square ducts
Area equation for circular ducts
Cubic equations
NOTE: Measurements made in inches
must be converted to feet or meters before using the above formulae.
Unit of Measure Conversion Table
m/s ft/min knots km/h MPH
1 m/s 1 196.87 1.944 3.6 2.24
1 ft/min 0.00508 1 0.00987 0.01829 0.01138
1 knot 0.5144 101.27 1 1.8519 1.1523
1 km/h 0.2778 54.69 0.54 1 0.6222
1 MPH 0.4464 87.89 0.8679 1.6071 1
Width (W)
Height (H)
Area (A) = Width (W) x Height (H)
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
Radius
Area (A) = pi
x r
2
Where pi = 3.14 and r
2
= radius x radius