Dispersing Unit

OASIS/L

Dry and wet dispersion in perfect combination

OASIS combines powerful dry and wet dispersers in a single device. It consists of the renowned dry disperser RODOS in the lower part and a special adaptation of the well-established wet disperser SUCELL on the upper part. Both units operate fully automatic under the control of the software or manually via the control panel

The change between dry and wet dispersion is done within a few seconds. Pressing a button on the control panel or giving a command by software and the flow through cuvette is lowered into the measuring position. All dispersion parameters such as pumping and stirrer speeds are set and the unit is ready for the operation of the wet disperser. A second command lifts back the cuvette into its protection housing. Now all parameters of the RODOS are set and the unit is ready for the operation of the dry disperser.

When performing dry measurements with RODOS, the dosing of the powder sample is performed by the precision vibratory feeder VIBRI, which guarantees optimum sample concentration in the free aerosol jet in the measuring zone through a consistent, controlled product supply. The perfectly coordinated combination of measuring range, dosing and dispersion enables a product-specific and precise and repeatable particle size analysis far into the submicron range. Feed rate, dispersion energy, position of the dispersing line and the trigger for the recording of measurements can be automatically reproduced – reliably for every measurement.

When switching to wet measurement the SUCELL flow cuvette extends at the push of a button into the measuring zone. Equipped with a stainless steel fluid basin with a nominal volume of 400 ml and a peristaltic pump, SUCELL is a proven solution for closed loop measurement tasks. For smaller sample volumes, a small volume adapter allows the analysis volume to be reduced to 50 ml. The powerful sonication is capable of dispersing even highly agglomerated suspensions directly in the basin. Two immersible stirrers reliably homogenise the sample, and the pump ensures that there is a steady flow through the measurement cuvette. Rinsing, filling, degassing, addition of additives, pump and stirrer speeds, sonication and the trigger for the measurement can be controlled using the operating panel or the software. Different materials are available for gaskets (FKM, EPDM, NBR, FFKM, silicone) and tubes to ensure that the chemical resistance is matched to the dispersing fluid (Marprene®, EPDM or CHEM-SURE®).

OASIS/L can be used with all laser diffraction sensors of HELOS series and with image analysers of QICPIC family allowing reliable particle size and particle shape analyses of dry powders, granules and fibres as well as suspensions with fine up to coarse disperse particles in one hybrid system.

Measured parameter Product state Range Sample volume
Particle size dry < 0.1 - 3,500 mm < 1 g - 1,000 g
Particle size wet 0.1 - 875 µm 50 or 400 ml
Particle size & shape dry 5 - 4,000 mm < 1 g - 1,000 g
Particle size & shape wet 2 - 2,000 µm 50 or 400 ml

As a special feature, the cuvette position of SUCELL/L is controlled by software along the optical axis at high precision. For image analysis this function is used as auto-focus on the measured particles, i.e. the software ensures, that the particles are always imaged at the maximum sharpness. For laser diffraction this function is used to position the cuvette automatically to the optimum working distance, which is depending on the measuring range.
Cuvettes with different optical path length are available

  • for laser diffraction with HELOS: 2 mm and 4 mm
  • for dynamic image analysis with QICPIC: 0.2 mm, 0.5 mm, 1 mm, 2 mm und 4 mm

The used cuvette type is automatically identified.

For operation of RODOS/L an extraction unit is necessary for sample collection and the generation of a laminar air flow in the measuring zone of the sensors.

Typical configurations

HELOS/BR + OASIS/L + VIBRI/L

HELOS/BR + OASIS/L + VIBRI/L

Laser Diffraction | Dry
Size range: 0.1 µm - 875 µm
Sample amount: < 1 mg - 1,000 g
Laser Diffraction | Wet
Size range: 0.1 µm - 875 µm
Analysis volume: 50 / 400 ml

Suited for

Typical applications

Applied for control of

HELOS/KR + OASIS/L + VIBRI/L

HELOS/KR + OASIS/L + VIBRI/L

Laser Diffraction | Dry
Size range: 0.1 µm - 3,500 µm
Sample amount: < 1 mg - 1,000 g
Laser Diffraction | Wet
Size range: 0.1 µm - 875 µm
Analysis volume: 50 / 400 ml

Suited for

Typical applications

Applied for control of

QICPIC + OASIS/L + VIBRI/L

QICPIC + OASIS/L + VIBRI/L

Image Analysis | Dry
Size range: 5 µm - 4,000 µm
Sample amount: 0.5 mg - 1,000 g
Image Analysis | Wet
Size range: 2 µm - 2,000 µm
Analysis volume: 50 ml / 400 ml

Suited for

Typical applications

Applied for control of