MSE SONIPREP 150, Инструкция по эксплуатации

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PROCESSING SAMPLES 14
3. PROBES
3.1 Description and Function
The probe is a resonant element used for the transmission of vibrating
mechanical energy from the transducer to the sample. The prime purpose of
the probe is to increase the transducer amplitude to a usable level or, to select
the acoustic power transfer. Ideally, material used for such probes should have
good acoustic properties, high fatigue strength, low acoustic loss and density. It
is essential that it should also be corrosion and erosion resistant and relatively
inert to the materials being sonicated. The material that possesses all these
qualities is titanium alloy and it is from this material that probes available for use
with the disintegrator, are manufactured.
Note: Probes are specially designed to suit the Soniprep 150 models and
are tuned to 23KHz.
3.2 Exponential Microprobe
This probe has been specifically designed for the treatment of small quantities
of sample, up to 5ml. It should, preferably, be used with the 20ml tube and
sealing cap but any other suitably sized tube may be employed.
3.3 Fitting a probe to the Transducer
Clean the mating surfaces of the probe and transducer with a soft cloth. Before
fitting the probe, screw the coupling stud into the transducer approximately
10mm leaving approximately 10mm protruding. Screw the probe onto the stud
in the transducer head, by hand. Then tighten firmly using a short screwdriver's
shaft located in the through hole in the probe.
It is important that the probe is clamped securely to the transducer, as failure to
do so will result in a large power loss and an irritating high-pitched noise.
NOTE: The coupling stud is a relatively loose fit in both the transducer
and the probe to ensure that the contact surfaces are allowed to mate
perfectly. An extremely small smear of silicone grease on the probe head
will facilitate surface mating.
3.4 Position of the probe in the liquid for treatment
When maximum power is necessary for a difficult application, the probe tip
should be immersed into the solution to an optimum depth.
As a guide, for 50ml sample down to 10ml sample, the best position for the
probe tip is 1cm below the surface of the sample. If the sample is less than
10ml, the best position for the probe tip should be found by trial and error.
Excessive depth and also the viscosity of the solution will cause the power to be
damped, which will be evident by a lower indication on the amplitude meter.
Conversely, if the probe tip is insufficiently below the surface, there will be a
tendency to generate foam in the solution or to cause scattering of droplets out
of the vessel. This is especially so when using high amplification. If the solution
foams, there will be a distinct change in sound, i.e. virtually unloaded and little
energy is being transferred to the solution.