Introduction/General Information - Spectronics Marksman II Série Mode D'emploi

relatively small that the sounds they produce are above the range
of human hearing. Most commonly, these faults generate sounds
in the 38,000 to 43,000 cycles per second range, generally referred
to as being in the ultrasonic range.
To employ the ultrasound methodology in a usable manner, it is
imperative that the listener have access to an audible sound that
bears a resemblance to the natural sound of the defect.
A mechanical bearing with a defective ball should sound like such.
Likewise, converting the ultrasound frequencies to audible
frequencies is not sufficient with regard to rendering a usable
signal. For this reason, the Marksman II incorporates a
process whereby the audible signal bears a close likeness to
the natural incoming sample. We call this process "Sound
Signature Technology," whereby a gas leak sounds like a gas leak
and a defective bearing sounds like one.
GENERAL INFORMATION
The Marksman II is sensitive only to ultrasound (40.5 kHz) and is
unaffected by audible noise. Internal Noise Control (I.N.C.) allows
the use of this instrument in extremely noisy environments such as
mechanical rooms, around operational chillers, etc. Drag your
finger upwards on the sensitivity touch pad to increase sensitivity
when experiencing little or no environmental noise. Drag your
finger downwards on the sensitivity touch pad to reduce sensitivity
in response to an increase in environmental noise. The I.N.C.
works much like a two-way radio squelch allowing only the
strongest and closest signals to penetrate the electronic wall built
by the I.N.C. circuitry.
Many variables can affect the amount of ultrasound generated by
the leakage of gas through an orifice. Such factors include the
pressure/vacuum versus the surrounding environment, how
smooth the edges of the orifice are, the diameter of the orifice, the
leak detector's distance from the orifice and the presence of air-
flow, which may dissipate the ultrasound. As you use the
Marksman II, keep in mind that these factors may affect your ability
to detect ultrasonic leaks.
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