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Online Viscometer
Reliable viscosity measurement


The Online Viscometer was developed with the goal of achieving measurements which are comparable with laboratory results and to provide a system which provides these accurate values permanently and without influencing the process.
The viscometer is fitted between two flange connections. The melt channel can be designed according to the customer´s specifications between D = 20 mm (0.8 inches) and D = 110 mm (4.3 inches). The unit includes the pump drive, the pump, pressure transducers, temperature sensors and the control and evaluation electronics. Electric or liquid/vapor heating is available (optional). The setting of process parameters, the evaluation and the display is realized via a user-friendly touch screen panel or alternatively can be integrated into an existing control system.
An easily exchangeable capillary permits the adaptation of the measuring device to different viscosities ranging from 1 mPas (0.01 poise) up to 20.000 Pas (200,000 poise). A subsequent change of the measuring range is also possible.
Due to the special melt channel design and precise fabrication, dead spots or edges in which shear- and temperature sensitive polymers could possibly stagnate can be avoided. The very short dwell time also prevents accumulations of degraded material. A further innovative feature is the possibility of completely cleaning all parts in contact with the melt without interrupting or disturbing the production process. Configuration


By means of a high precision metering gear pump, a small part of the polymer melt (max. 3 kg / h or 7 lbs / h) is separated from the main melt channel. This is pumped through a precisely manufactured slot capillary. The inlet and outlet pressures or the elastic properties which disturb the measurement are filtered out by means of length – optimized inlet and outlet zones in the capillaries for levelling out the laminar flow. Advantages
  • No measurable temperature increase in the rheometer thanks to ample flow channels.
  • Short dwell time, no dead spots, no remains in the melt channels.
  • Through measurement in the rectangular capillary cross section – no elastic properties are recorded.
  • Very compact design, flexible adaptation to the existing melt pipe or extrusion line.
  • Fast adaptation and change of the measuring range through an exchangeable capillary plate.
  • Polymer bypass, therefore no melt losses.
  • High-precision measurement of the melt temperature directly during the viscosity measurement.
  • High measurement accuracy through use of special high-precision pressure transducers.
  • Complete cleaning of all surfaces and channels in contact with the melt without interruption or shutting down of the production process.