Particle sizing of fine dry powders with the renowned dry disperser RODOS/M with vibratory feeder VIBRI/R in the measuring zone of
the laser diffraction sensor HELOS/BR.
The RODOS/M is an universal dry dispersing unit applicable for nearly all kinds of dry powders with particle sizes in the range from < 0.1µm to about 3500µm. The patented combination of feeding and dispersing enables a smooth, complete, product adaptable dispersion, which is widely extended into the SUBMICRON range.
Using compressed air to disperse even the finest powder this module generates a dry aerosol which is blown through the laser beam and collected in a suction after the analysis. Particle-particle-collisions, particle-wall-collision and velocity gradients are applied within the RODOS injector for complete dispersing of the sample. The dispersion energy can be adapted to the demands of the product.
RODOS/M as the fully automated version of RODOS is completely controlled by software. The correct product dependent dispersion force is automatically chosen by the software's database. This makes RODOS/M ideal for validated applications e.g. in the pharmaceutical industry. The sample feeding for RODOS & RODOS/M can be done by VIBRI or the micro-dosing device ASPIROS. For special applications RODOS and the measuring zone can be enclosed.
If not only dry powder analysis is your daily lab business but also suspensions and emulsions are analysed, RODOS/M can be extended by SUCELL/M into the multifunctional dry and wet dispersion module OASIS/M.
For the optimum adaptation to the particles size the RODOS/M dispersing line is available with inner diameters of
recommended for 0.1 µm < xmax < 1000 µm,
|recommended for 1 µm < xmax < 2000 µm) and|
|recommended for 10 µm < xmax < 3500 µm.|
RODOS/M can be used with all members of the HELOS family. For the operation an extraction unit is required for the sample collections and the generation of a laminar air flow in the measuring zone of the HELOS.
Prerequisite of a good dispersion is a smooth and homogeneous dosing. Two different dosing options are available: The vibratory feeder VIBRI serves most of the applications. For applications requiring micro-dosing please refer to the ASPIROS.
Laser Diffraction Sensors
RODOS/M with VIBRI/R open measuring zone with particles "glowing" in the laser beam
RODOS/M with vibratory feeder VIBRI
Following the vacuum generated through expansion of compressed gas applied to the injector, the agglomerates of fine dry particles arrive at low speed in the dispersing line and are subject to immediate acceleration. Three effects are available for the dispersion:
1. particle-to-particle collisions,
2. particle-to-wall collisions and
3. centrifugal forces due to strong velocity gradients.
The standard mode operation of RODOS/M is via control with the WINDOX software. The RODOS/M can also be operated manually via the operational panel.
The panel allows for the control of Start/Stop of the different dosing units, and the extraction unit, the setting of the primary pressure and the vacuum level of the disperser.