Bacharach Tru Pointe 2100, Руководство по эксплуатации и обслуживанию

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Tru Pointe® 2100 Instruction 0028-9003
6
Principle of Operation
The principle of operation of the Tru Pointe
®
2100 is based on the turbulent fl ow of fl uids and
gasses. Turbulent fl ow has a high content of ultrasound, which the Tru Pointe ® 2100 can detect.
Imagine air leaking from a tire. Because this is such a large leak, your ear can detect this sound,
however your ear hears only about 1/3 of the actual spectrum of sound which exists. The sound
of small leaks is mostly ultrasonic which your ear can not detect.
EXAMPLE: A piece of straight tubing connected to a
gas supply and left free to exhaust into the atmosphere
will not generate sound if the volume of gas through
it is such that turbulence does not take place. Yet for
that same
fl ow, an opening as small as 0.005 of an inch
could generate enough sound to be heard several feet
away.
For a leak to happen there must be an opening in the system that carries a gas or fl uid. Normally,
these openings are not clean smooth holes, but passages through cracks with many jagged
edges and internal chambers. Fluid or gas escaping through an “ori
fi ce” like this, is forced into
turbulence, random circular-like motions. Inside a tube where a gas may be fl owing, the fl ow is
normally laminar which means that a given layer of gas does not mix with layers above it or below
it. This condition happens in a straight long tube when the velocity of the
fl uid is not high. A gas
leaking out of a straight and long tube will not generate as much sound as if it were leaking out of
a small crack because the
fl ow is not turbulent.
The intensity of sound generated at a leak is a very complex function of the viscosity, the tem-
perature, the speed the
fl uid is moving, the Reynolds number, the pressure differential across the
leak, and the physical dimensions and characteristics of the ori fi ce. This is why it is impossible to
quantify the size of a leak with ultrasonic technology. A smaller leak may generate more sound
than a larger one.
The Tru Pointe ® 2100 detects ultrasound NOT the presence of a speci fi c gas. It is NOT a gas
“Sniffer”. Because of this fact, the Tru Pointe
®
2100 can function in areas where heavy wind or a
concentration of fumes renders other detectors useless.
WARNING! Ultrasonic detectors will not indicate a
leak if there is no turbulent fl ow producing sound when
checked. If you suspect a toxic gas, natural gas, or
other combustible gas leak and it is not detected by the
Tru Pointe
®
2100, do not assume it doesn’t exist, and
use another method as veri fi cation there is no gas leak
present.