model 3500 viscositymeter
Viscosity transducers for process installations
The ViscoTron sensor series VP-3500 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-3500 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-3500 is available in versions to measure low, medium or high viscosities. Sensors can be constructed for pressures up to 1 MPa (150 psi) and temperatures up to 240˚C (465˚F). The systems are factory calibrated using Newtonian ASTM traceable ﬂuids.
The viscometer torsionally displaces the sensor bulb. The drag on the twisting motion is a measure of the viscosity. Speed, direction and turbulence of ﬂow have no inﬂuence on the measurement.
The resonant frequency is dependent on the mechanical construction of the sensors and typically between 400 and 600 Hz. The microscopic motion is fast enough to be separated from outside mechanical vibrations, yet low enough to provide excellent sensitivity and resolution for newtonian and non-newtonian ﬂuids.
The sensor shown in the picture to the right with an internal VT-IRFTi transmitter has been designed for low viscosities, low pressures and process temperatures up to 175˚C. Air cooling of the sensor housing is not required. Eliminating air cooling lowers operating cost and eliminates temperature variations at the sensor bulb, which can result from air cooling the housing. An optional temperature probe placed close to the sensor is ﬁeld serviceable. Alternatively a temperature probe can be placed directly inside the sensor.
ViscoTron series 3500 sensors are also available as an exproof version providing the same performance as the general purpose 3503 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.