TSI Alnor LoFlo Balometer El Manual Del Propietario página 15

Hoods
Hoods may be cleaned in cool water with a mild
detergent.
Sensing Manifold
The manifold should be checked visually before using
to be certain that the sensing holes have not become
clogged with dirt or dust particles. Do not immerse the
manifold in water. It is recommended that cleaning be
done with extreme care with the manifold in place. Do
not use highly compressed air to clean the manifold
tubes.
Calibration
It is recommended that your LoFlo Balometer
Hood be returned to the factory once a year for a
calibration check. When shipping the LoFlo
®
Balometer Capture Hood for factory calibration, pack
it carefully, and follow the Instructions for Return in
this manual.
Vent Operation
If the vent becomes difficult to operate, remove both
thumbscrews from the vent mechanism and spray the
contacting surfaces with silicone spray lubricant. Wipe
off excess and reassemble vent mechanism.
9
SECTION 9
Maintenance
Performance Check
If the calibration is to be checked, the best way is to use
a reference flow standard more accurate than the LoFlo
Balometer
used for this purpose include orifice plates, venturis,
nozzles, and laminar flow elements. These devices
require accurate differential pressure, barometric
pressure, and temperature reading instruments to
measure either actual or standard volume rate.
If the LoFlo Balometer
against a velocity instrument such as a pitot
probe/manometer or thermo-anemometer, there may be
errors. If a velocity standard is used, the average
velocity must be obtained by taking a traverse.* The
accuracy of the traverse is dependent on the flow
uniformity, the number of readings taken, the accuracy
of the velocity instrument, and operator expertise. This
®
Capture average velocity reading must then be multiplied by the
area over which the traverse was taken.
Finally, air flow instrumentation is 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
pattern which will provide an overall velocity value when
averaged together. Any of the Alnor velocity measuring
instruments can be used for this purpose.
®
Capture Hood. Flow standards that may be
®
Capture Hood is checked
9