Shortridge Instruments ADM-860C User Manual

ADM-860C 04/14/0851
barometric pressure must also be in metric units. Many Dew Point/Vapor Pressure conversion charts are in
metric units.
Local air density velocity readings may be corrected for relative humidity using the following formula.
Where: P
b
= local barometric pressure
V
dry
= velocity corrected for local density (temperature and barometric pressure)
P
vapor
= vapor pressure
Local air density air flow readings may be corrected for relative humidity using the following formula.
Where: P
b
= local barometric pressure
F
dry
= air flow corrected for local density (temperature and barometric pressure)
P
vapor
= vapor pressure
13.5 HOT WIRE ANEMOMETER VERSUS AIRDATA MULTIMETER
The ADM-860C AirData Multimeter measures local density true air velocity. This is in contrast to thermal
anemometers or "hot wire" instruments which measure mass flow (mass flux/unit time). Mass flow represents
the number of molecules of air flowing past a given point during a given time. Mass flow only represents true
velocity when measured at standard sea level conditions of 29.921 in Hg and 70
/ F (0.075 lbs/cu ft). Hot wire,
mass flow, "velocity" readings at density conditions other than standard must be corrected for local air density
conditions if these results are to represent true air velocity.
Local density velocity readings taken with the ADM-860C AirData Multimeter may be compared with hot wire
anemometer readings if the hot wire readings are corrected for local air density conditions to obtain true air
velocity results.
The precise method for calculating local density corrected air velocity from measurements taken with a hot wire
anemometer requires the use of the following equation:
Where: P
b
= local barometric pressure (in Hg)
/ F = temperature of airstream

Shortridge Instruments ADM-860C Specifications

General

Brand	Shortridge Instruments
Model	ADM-860C
Category	Measuring Instruments
Language	English