Monitoring deflocculated particles in a suspension

Apparatus for monitoring the deflocculation of particles in a liquid suspension, which particles, when deflocculated, are such that they can become aligned in an applied field, the apparatus comprising first means, for providing a monitoring region into which at least a part of said suspension is supplied;

• second means for applying a beam of radiation to said region;
• third means, for producing a disturbance field in said region, said field being in a direction parallel to the direction of said beam of radiation, and fourth means, for detecting a change, if any, in the forward radiation scattering properties of the suspension with respect to the beam in said region due to the aligning of deflocculated particles of said suspension in said region, said third means being suitable for applying such a field to such a region of a first sample of suspension whose degree of deflocculation is desired to be monitored and for applying such a field to such region of a second sample of suspension, whose particles are known to be substantially fully deflocculated, said fourth means being suitable for detecting the change in radiation scattering properties of each region due to the field to produce a respective output indication and the apparatus further comprising means for comparing the indications to produce an indication related to the degree of deflocculation of the particles in the first suspension.