UE Systems Ultraprobe 3000, Инструкция по эксплуатации

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Ultraprobe applications
1. Leak detection
This section will cover airborne leak detection of pressure and vacuum systems. (For information
concerned with internal leaks such as in Valves and Steam Traps, refer to the appropriate
sections).
What produces ultrasound in a leak? When a gas passes through a restricted orifice under
pressure, it is going from a pressurized laminar flow to low pressure turbulent flow (Fig. 1). The
turbulence generates a broad spectrum of sound called "white noise". There are ultrasonic
components in this white noise. Since the ultrasound will be loudest by the leak site, the detection
of these signals is usually quite simple.
Figure 1: Pressure Leak
Figure 2: Vacuum Leak
A leak can be in a pressurized system or in a vacuum system. In both instances, the ultrasound will
be produced in the manner described above.
The only difference between the two is that a vacuum leak will usually generate less ultrasonic
amplitude than a pressure leak of the same flow rate. The reason for this is that the turbulence
produced by a vacuum leak is occurring within the vacuum chamber while the turbulence of a
pressure leak is generated in the atmosphere (Fig.2).
What type of gas leak will be detected ultrasonically? Generally any gas, including air, will produce
a turbulence when it escapes through a restricted orifice. Unlike gas specific sensors, the
Ultraprobe is sound specific. A gas specific sensor is limited to the particular gas it was designed to
sense (e.g., helium). The Ultraprobe can sense any type of gas leak since it detects the ultrasound
produced by the turbulence of a leak. because of its versatility, the Ultraprobe may be utilized in a
wide variety of leak detection. Pneumatic systems may be checked, pressurized cables, such as
those utilized by telephone companies, may be tested. Air brake systems on railroad cars, trucks,
and buses may be checked. Tanks, pipes, housings, casings and tubes are easily tested for
leakage by pressurizing them. Vacuum systems, turbine exhausts, vacuum chambers, material
handling systems, condensers, oxygen systems can all easily be tested for leakage by listening for
the turbulence of the leak .