Uson sprint iq, Руководство пользователя

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Reference
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This difference in air density can cause variations in flow
readings from one location to another when elevations are
quite different and no corrections are made.
Sprint IQ measures true air flow in units standardized to 29.92
inHg (14.68 psi) at 20 degrees C. Although the Sprint IQ’s
measurements are accurate and traceable to NIST standards,
flow readings could be different if the tester is used at
drastically different altitudes. This is not a tester fault; rather,
conditions have changed and Sprint IQ measures this
difference. At a high altitude, air is less dense than air at a
lower elevation. When compressed to the same relative
pressure, the air will exhibit a density shift when compared
with air compressed to the same relative pressure at a lower
level.
Difference in air density is the primary reason users can
observe slightly different results when temperature and gauge
pressures are identical. For this reason, it is important to
establish all test parameters at the same altitude and under the
same conditions in which the tester will be used.
Compensation may be necessary to reconcile air density
variations between the two locations if measurements are
made at different altitudes.
Fluids vs. Solids
The distinguishing feature of a fluid (gas or liquid), in
contrast to a solid, is how easily the fluid can be deformed. If
a shearing force, even a very small force, is applied to a fluid,
the fluid will move and continue to move as long as the shear
acts on it. For example, the force of gravity causes water
poured from a cup to flow. Water continues to flow as long as
the cup is tilted. If the cup is turned back up, the flow stops
because the gravitational force is then exactly balanced by
force of the cup wall.