- -
47
AP471…,
AP472…
AND
AP473…
P
ROBES FOR THE MEASUREMENT OF
A
IR VELOCITY EQUIPPED WITH
SICRAM
M
ODULE
The probes of AP471, AP472 and AP473 series are to be connected to a DO9847 multifunction in-
strument to measure velocity and flow of an incident airstream. Some of these probes can also
measure air temperature. Applied principles of measurement are three: hot-wire for the AP471 se-
ries, vane for the AP472 series and Pitot tube for the AP473 series. On request the probes of AP471
and AP472 series can be equipped with a telescopic shaft to make measurements in hard-to-access
areas (such as in vents, or in duct inlets/outlets) easier.
Their main applications include: the control of air velocity and flow on conditioning, heating and
cooling plants, the definition of ambient comfort, etc.
Hot-wire probes are generally used for accurate measurements in environments with a medium-low
air velocity (up to 10 m/s), vane probes in environments with air velocity from 5 to 50m/s, Pitot
tube probes in environments with air velocity higher than 40m/s.
The temperature of the fluid to be measured has to be also taken into consideration: hot-wire probes
measure streams having an 80°C max. temperature, vanes reach 120°C, while Pitot tube probes
measure the velocity of air streams having temperature up to 600°C, according to the model.
Measurements provided by these probes are:
•
air velocity (variable identified by number 1, that is A1, B1 or C1),
•
air temperature (variable identified by number 2, that is A2, B2 or C2),
•
flow (variable identified by number 3, that is A3, B3 or C3).
The probes of AP471, AP472 and AP473 series provide three different measures at the same
time (air velocity, air temperature and flow). To view the three measurements contemporane-
ously, no other probe has to be connected to the instrument.
Insert the connector with the SICRAM module in one of the inputs (i.e. “A”) and then turn the in-
strument on. Should the display indicate that an input variation has occurred, wait for a few sec-
onds. The instrument will turn off and then on again, displaying the 3 measurements: A1 (velocity),
A2 (temperature) and A3 (flow). If the probe is not equipped for measuring temperature, only A1
(velocity) and A3 (flow) variables will be viewed.
Press <9/UNIT> to select the units of measurement of the displayed instantaneous value. The fol-
lowing units are available:
•
m/s, km/h, ft/min, mph, knots for air velocity;
•
°C, °F and °K for air temperature;
•
l/s, m
3
/s, m
3
/min, ft
3
/s, ft
3
/min for flow.
Ti
A1
a2
a3
F1
