Dispersion of coarse dry particles by the gravity disperser GRADIS/L combined with the
vibratory feeder VIBRI/L inserted in the measuring zone of a HELOS/KR laser diffraction sensor.
This unit is ideal for products that do not need a high dispersing energy, like crystals, sand, granules etc. The fall shaft provides smooth dispersion and controls and equals the speed of the particles presented to the laser beam. GRADIS/L is fed by VIBRI/L, the software controlled feeding device for QICPIC and HELOS dry dispersing modules. The GRADIS/L is typically operated together with an extraction unit for the particle collection and the generation of the laminar air flow. If required, the sample can be collected and re-used after the analysis.
The GRADIS/L can be used for the analysis of very coarse particles and sample quantities up to the kilogram regime.
The width of the outlet slit of the fall shaft can be manually set to 2 mm, 4 mm or 10 mm. This is used for image analysis application to keep the particles within the working distance of the imaging objectives.
The fall shaft can be separated into two halves for cleaning purposes. For special applications fall shafts with PTFE coatings (conducting or non-conducting) are available as an option.
GRADIS/L can be used with the HELOS/KR, HELOS-VARIO/KF laser diffraction sensor or QICPIC image analysis sensor family.
GRADIS/L and VIBRI/L
on parking stand
The particles in the fall shaft are accelerated by the gravity of earth. Two mechanism are used for dispersion:
and particle-to-particle collisions.
For a comfortable operation, the operating panel of the VIBRI/L is duplicated at the front of the GRADIS. Start/Stop, feed rate and gap width of the VIBRI/L funnel can be set manually.
Laser Diffraction Sensors