model 4500 viscositymeter
The ViscoTron sensor series VP-4500 has been developed employing experience gained over more than 25 years of applying, developing and manufacturing torsional motion viscometers.
Laser welded construction and innovative LED assisted assembly allows the series VP-4500 sensors to be manufactured to exacting standards and competitive prices. Laser welding replaces fastening of internal items with a ﬁxed method resulting in a stable measurement.
The series VP-4500 sensors can be manufactured to match customer application requirements by using any length or shape of extension.
The series VP-4500 is available in versions to measure very low, low, medium, high or extra high viscosities. Sensors can be constructed for pressures up to 50 MPa (7,250 psi) and temperatures up to 450˚C (840˚F). The systems are factory calibrated using Newtonian ASTM traceable ﬂuids.
The systems are adaptable to changing customer needs, without having to reconstruct the sensor. The sensors are gravity independent and can be mounted in any direction. Speed, direction and turbulence of ﬂow have no inﬂuence on the measurement.
The viscometer torsionally displaces the sensor bulb. The twisting motion at the natural resonance of the sensor creates a shear wave. The drag of the ﬂuid on the sensor surface is a measure of the viscosity.
The resonant frequency is dependent on the mechanical construction of the sensor and typically between 200 and 400 Hz. The speed of the microscopic motion is low enough to provide excellent sensitivity and resolution for newtonian and non-newtonian ﬂuids.
The resonant frequency and hence shear rate can be manipulated at the factory to be the same for multiple sensors. Electromechanical hardening of the VP-4500 provides high resistance to external mechanical vibration.
The sensor shown in the picture on the left has been designed for medium viscosities, low pressures and temperatures up to 350ºC. The sensor does not require air cooling. Eliminating air cooling lowers operating cost and eliminates temperature variations at the sensor bulb, which can result from air cooling the housing.
ViscoTron series 4500 sensors are also available as an ex-proof version providing the same performance as the general purpose 4504 version.
ViscoTron VT-IRFT transmitters measure the natural resonance response of the sensor. The measured power of the Fourier transform at the resonant frequency is equivalent to the viscosity. Using FFT Inﬂuences from external mechanical vibrations at other frequencies are eliminated at the source.