model 5500 viscositymeter
The VP-FT5500 series of ﬂow through viscosity sensors has been developed employing experience gained over many years with our process viscometers. Using the same torsional vibration principle, the ﬂow through transducer is capable of measuring viscosities accurately over a very wide range in real time.
The sensor has a straight ﬂow through Path. There are no bends or restrictions and therefore can be easily cleaned with foam pigs commonly used in some applications, should this be required. The straight ﬂow through tube makes the sensor rugged and virtually maintenance free.
Laser welded construction and innovative assembly allows the series VP-FT5500 sensors to be manufactured to exacting standards at competitive prices. Laser welding replaces alternative mounting methods of internal components and provides a stable measurement environment.
The series VP-FT5500 is available in versions to measure very low, low, medium and high viscosities. Sensors can be constructed for pressures up to 10 MPa (1,440 psi) and temperatures up to 175˚C (350˚F). Factory calibration with Newtonian ASTM traceable ﬂuids over two decades is standard with three decades optional.
The viscometer creates a shear wave by torsionally resonating the tube. The drag of the ﬂuid on the twisting motion is a measure of the viscosity. The system is factory calibrated using ASTM traceable standards. Speed, direction and turbulence of ﬂow have no inﬂuence on the measurement.
The resonant frequency is dependent on the mechanical construction of the sensor and typically between 200 and 600 Hz. The microscopic motion is fast enough not to be inﬂuenced by outside mechanical vibrations, yet low enough to provide excellent sensitivity and resolution for newtonian and nonnewtonian ﬂuids.
For ﬂuids which easily adhere to walls, the housing can be heated or cooled with a ﬂuid or electrical heating tape. A PT100 is optionally provided to measure the internal housing temperature. Low friction coatings for the ﬂow through tube are available as an option.
The VP-FT5500 series works with ViscoTron VT-IRFT induced resonance transmitters. ViscoTron VT-IRFT transmitters induce the natural resonance response in the measuring tube. Applying a fast Fourier Transform (FFT) algorithm provides accurate frequency measurement of the natural resonance. Measuring the power of the Fourier Transform at the resonant frequency is a measure for the viscosity.