Amprobe ULD-420 사용자 설명서 - 페이지 5
{카테고리_이름} Amprobe ULD-420에 대한 사용자 설명서을 온라인으로 검색하거나 PDF를 다운로드하세요. Amprobe ULD-420 15 페이지. Ultrasonic leak detector
페이지 인쇄1.888.610.7664
2. INTRODUCTION
Ultrasonic sound, or ultrasound, is a sound wave with frequencies above 20 kHz, higher
than the upper audible limit of human hearing. Ultrasound can be generated when
turbulence created by air or gas is forced through a small orifice. Leaking air or gas is
generally considered to be viscous flow, and as the flow velocity increases, the frequency
of the ultrasound emitted becomes higher. Vibrating, moving objects or electric discharge
will also create an ultrasonic wave, which is very directional in nature and can be used to
pinpoint the exact location of a leak, vibration or discharge.
The ULD-400-R Receiver detects ultrasounds within 20 kHz to 90 kHz frequency, then
amplifies and converts these ultrasonic sounds to frequencies and levels that the human
ear can hear through headphones and show it on the LCD screen. The 20 kHz to 90 kHz
frequency range is the optimal range for detecting a variety of leakage events in assets such
as HVAC systems and pneumatic lines. A change in the ultrasound produced by an asset may
be indicative that an asset is beginning to fail.
0
20 Hz
Infrasound
Acoustic Sound
Figure 2: Sound range spectrum
www.calcert.com
15
10
20
5
25
0
30
20 kHz
20 MHz
Ultrasound
3
200 MHz