Samples can probably be measured if the fine particles are submicron in size or smaller.
With an EMS viscometer, the sample and a spherical aluminum probe are placed in the sample container. A magnet positioned opposite the center of this aluminum sphere is rotated, producing a rotating magnetic field in the vicinity of the aluminum sphere.
A tiny induction current is generated inside the spherical aluminum probe at a distance by this rotating magnetic field. Further, a torque acts on the aluminum sphere due to the Lorentz interaction between this induction current and the rotating magnetic field. As a result, the aluminum sphere rotates in the same direction as the rotating magnetic field.
As the spherical probe drags along the sample, it rotates at a speed corresponding to the viscosity of the sample.
The viscosity is calculated from the rotational speed in this case, which is measured optically.
When the sample contains fine particles, if sedimentation inadvertently changes this dispersion, it will have an effect on the measured viscosity, and the measurements might not stabilize.
If these fine particles are 10 μm or larger, sedimentation becomes highly likely.
Note that the theoretical rate of sedimentation at 1 μm or smaller is 13 mm/h.
In addition, if the fine particles get into the gap between the sample container and the spherical probe, they might perturb the rotation of the spherical probe or impede detection of the rotation, so the feasibility of measurement will likely need to be investigated.
If you are interested in a measurement feasibility investigation or demonstration measurements, contact your KEM representative.