Performance Check - TSI Alnor Balometer 6461 Manual Del Usuario

When checking the performance of the Balometer,
first verify that the unit has been properly adjusted
to zero. If the calibration is to be checked, a
reference flow standard at least 4 times more
accurate than the Balometer should be used. Flow
standards that may be used for this purpose
include orifice or venturi flow meters or laminar
flow elements. These devices require accurate
pressure and temperature reading instruments to
measure actual flow volume.
If the Balometer is checked against a velocity
standard such as a Pitot-static probe or thermal
anemometer, the user should be aware that this
may introduce errors. If a velocity standard is
used, the average velocity must be obtained by
taking a traverse.* The accuracy of this average
reading is dependent on the flow uniformity, the
number of readings in the average and the
accuracy of the velocity reading instrument. This
average velocity reading must then be multiplied
by the area over which the traverse was taken. If
this area is not accurately measured, additional
errors in the final flow volume reading will result.
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PERFORMANCE CHECK

Finally, air flow instrumentation is often
dependent on environmental conditions such as
temperature, atmospheric pressure, humidity and
even turbulence. These conditions can have very
different effects on various instrument types.
Caution must be exercised when making
comparisons.
* A traverse is a set of velocity readings taken in a
prescribed geometric pattern which will provide
an overall velocity when averaged together.
Figure 8—Backpressure Curve