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Transmit Pulse
The DPS300 transmit pulse consists of one or more electrical "shot" pulses, which
are supplied to the scanning relay. The scanning relay is activated as required, to
supply the transmit pulse to the Transducer(s) connected to the DPS300
terminals.
The transducer fires an acoustic "shot" for each electrical pulse supplied. After
each shot is fired, sufficient time is provided for echo (shot reflection) reception,
before the next (if applicable) shot is fired. After all shots of the transmit pulse are
fired, the resultant echoes are processed.
The InterRanger™ DPS300 uses a dual frequency transceiver to provide more
accurate results than a single frequency system. A low frequency is used to
achieve good penetration in sludge where a lot of suspended solids are present,
and at the same time a high frequency is used to obtain reflections from lighter,
less dense sludge layers.
Transducer
The Siemens XCT12 transducer is a very versatile transducer because it can be
used at several different frequencies outside its normally selected frequency. This
effect comes from the higher order vibrational 'modes' that exist in any physical
structure. In the case of the XCT12 transducer the high frequency used is
150KHz. The transducer is a powerful emitter at its lower frequency (42KHz) and
this effect is useful both for good penetration in certain sludge types and for
keeping the transducer's active face clean for longer periods of time.
Beam Patterns
The transducer's beam pattern changes in water because the speed of sound is
much higher (1483m/s @ 20°C) than in air (343m/s @ 20°C). As shown in the
polar response graph, the 150 kHz beam pattern has a fairly narrow centre beam
with residual side-lobes, and the larger, elliptical plot illustrates the 44Khz
response. Radial divisions are in 10dB steps.
7ML19981BC01
TECHNICAL REFERENCE
Beam Pattern
for XCT-12.
95
InterRanger DPS300
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