9
Use on Grilles
Better measuring conditions can be obtained on
grilles with adjustable direction vanes if the
vanes on the grilles are temporarily straightened
before making measurements. This should not
significantly affect the flow rate as long as any
built in dampers are not accidentally disturbed.
It is advisable to use the aperture (the actual
effective area of air flow), not the surface area
of the grill, in any flow rate calculation. The
RVA+ is suitable for both supply and exhaust
grilles, and the procedure for both is the same
except that the direction arrow on the
instrument head must be aligned correctly with
the direction of the air flow. The head should be
held close to the grille on exhaust, but the head
should not touch the grille.
“Sweep” Technique
In addition to traditional traverse methods some
users prefer to use a “sweep” technique. A
continuous and uniform movement of the
RVA+ over the entire measurement plane while
READ key is depressed will produce a time
averaged reading.
Users attempting to rely solely on this method
should verify their “sweep” technique against
conventional traverse methods.