| 摘要 |
The invention relates to a measurement sensor making it possible to assess the particle concentration, and more particularly the microorganism concentration, in a liquid medium. The sensor is composed of two parts: - a chamber (1) connected to a system making it possible to create in it a reduced pressure measured by the torque exerted by the motor (11) which drives the movement of a sealed bellows (18); - a membrane (2) separating this chamber from the suspension or the solution to be studied; this membrane is of organic or inorganic (sterilisable) nature and has variable porosity, matched to the suspension or to the solution to be studied. A relationship is set up between the particle concentration and the progressive clogging of the membrane by these particles. With a reduced pressure having been created in the chamber (1), the time necessary to reach equilibrium is measured. This time will be commensurately longer as the particle concentration is small. Two measurement principles can be used: - measuring the time necessary to reach a fixed pressure (close to equilibrium); - measuring the pressure reached at a given time. The invention may be used both for measuring the particle distribution in a suspension and for determining the viscosity of polar solutions; in the latter case, it is the presence of the polymers which leads to the clogging of the membrane. <IMAGE>
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