Application Note

2 Fluke Corporation The multifunction Fluke 975 AirMeter™ tool is money in the bank for busy HVAC technicians
Big capability, small
package
The Fluke 975 AirMeter™ tester
delivers multiple measure-
ment capabilities in a compact
package. It’s designed to be
easy and intuitive to use, yet
it packs enough power and
sophistication to satisfy the
most advanced power users.
A rechargeable lithium
battery powers the Fluke 975
and will operate the meter
for 11 hours on a full charge.
Three AA batteries may be
installed for an additional
seven hours of backup. The
power adapter recharges the
lithium battery and will oper-
ate the meter continually.
The Fluke 975 stores read-
ings of all measured air qual-
ity parameters in its internal
memory. Users can download
the stored data to a PC using
the tester’s integrated USB
interface. They can then use
FlukeView
®
Forms software,
which is included with the
Fluke 975, to analyze and
display the data and create
custom reports. When the meter
is left at a site for data logging,
a Kensington lock (not included)
can be used to secure it.
When powered on, the Fluke
975 performs a 35 second
startup and self test and deter-
mines absolute barometric
pressure, which the meter uses
for automatic compensation for
such functions as air velocity
and psychrometrics (the interre-
lationship of air, density, mois-
ture, temperature and heat).
The Fluke 975 features
field calibration capability to
help maintain accuracy while
eliminating the need to send
the instrument out for recom-
mended routine calibration of
the CO sensor (monthly) or the
CO
2
sensor (annually).
time, the Fluke 975 gathered
accurate and comprehensive
information on air conditions
that he could then share with
building tenants.
“I can ask if it’s too hot or too
cold in an area, and the occu-
pants will tell me,” Klockow
says, “but with the Fluke 975
I was able to establish a good
baseline.”
A breath of fresh air
Another key feature was the
Fluke 975’s calculation of
percent outside air. The Fluke
975 AirMeter™ tester calcu-
lates the portion of outside
air included in the ventilation
mix in two ways, using CO
2
or
temperature.
“It’s huge,” Klockow says.
“You have to have outside air,
a 10 percent minimum in the
new buildings. Buildings are
all so tight now; they don’t
have air leaks, so you need to
have that outside air coming in
to help with the outgassing of
carpets and furniture and with
creature comfort. You’ve got to
have that fresh air in there.”
For most field techs, estimat-
ing the percentage of outside
air entering the ventilation
system involves a visual
inspection of the air intake,
followed by a best guess. But
the Fluke 975 enabled Klockow
to sample air conditions, and
then calculate the percentage
of outside air actually entering
the system.
“That’s one of the things that
was great for me,” Klockow
says. “I was able to make
sure that I’ve got an adequate
amount of outside air coming
in, and feel confident that I
knew we’ve got outside air
coming in.”
CO-CO
2
-temperature-
relative humidity
After the meter completes its
startup test, the main screen
simultaneously displays
temperature (°F or °C), rela-
tive humidity (% RH), CO
ppm (parts per million), and
CO
2
ppm. Soft keys let the
user toggle between wet
bulb temperature (WBT) and
dew point temperature (DPT).
When the “MIN MAX” button is
pressed, the meter will begin
to record the minimum, maxi-
mum, and average of all avail-
able readings, including air
velocity if the detachable air
velocity probe is connected.