본 점도계는 가압 조건에서도 점도 측정이 가능하며, 주로 저점도의 시료를 측정하는 데 사용됩니다.
분석 문의하시면 1주일 이내 데이터 제공하고 측정 보고서 발행 가능합니다.
Shear Rate를 제어하는 경우 스핀들 회전형 점도계가 사용됩니다.
Fundamentals of quartz viscosimetry
Starting point
The principle of quartz viscosimetry is based on the idea of W.P. Mason. The basic concept is the application of a piezoelectric crystal in the shape of a torsional oscillator for the determination of viscosity. On the one hand, the high-frequent electrical field that is applied to the oscillator causes a movement of the sensor and in consequence the shearing of the fluid. On the other hand, the movement of the sensor is influenced by the external forces (the shear stress) of the fluid which affects the electrical response of the sensor.
Development of the quartz viscosimeter QVis
The calibration procedure as a prerequisite of viscosity determination using a quartz goes back to the founder and CEO of flucon fluid control GmbH B. Bode who facilitated the detailed analysis of the electrical and mechanical transmission behavior of the oscillating system. On the basis of this calibration, the quartz viscosimeter was developed which allows continuous viscosity determination in resting and flowing liquids.
The QVis is comprised of two components, the electronic unit equipped with an electronic control and evaluation system on the one hand, and the measuring head which surrounds the quartz on the other hand. The micro processor which is part of the electronic unit is responsible for determining the oscillating behaviour of the quartz crystall sensor. With the help of the calibration function, the viscosity is determined in a next step.
Advantages of viscosity measurements by means of a quartz sensor
- no molecular destruction of the measuring fluid
- no temperature effects on the measuring fluid
- small sample sizes sufficient
- large measuring range (1 to 10.000 mPas)
- chemical resistance of the quartz sensor
- suited for temperatures up to 500°C and pressure up to 10 kbar
- resistant against dirt and deposits
- easy to clean
Accurate and versatile
The core of the QVis viscosimeter is an oscillating quartz which is robust and versatile: with its wear-free crystal QVis can determine the dynamic viscosity of both resting and flowing liquids. Being fully independent of the flow conditions, your liquid can even have turbulences.
And here is how QVis works: Once immersed into the test liquid the oscillating behavior of the quartz changes. Each influence on the oscillation has specific characteristics and will be analyzed thoroughly by the flucon device to determine the viscosity. This patented, tried and trusted measuring method makes our QVis a unique instrument that opens up many new possibilities for the determination and for the control of viscosity.
Key features
- Available for both inline/process and laboratory applications
- Measurement of the dynamic viscosity and temperature
- Simultaneous display of the kinematic viscosity
- Determination of the viscosity independent of the direction of flow
- High shear-rates without adverse effects on the test fluid
- Large measuring range (1 to 10.000 mPas)
- Only small samples required for measurements (approx. 35 ml)
- Short set-up and measuring times
- Easy to handle and to clean
- Robust quartz sensor without any moving parts
- Standard digital interface (RS-232) for optional connection to your WINDOWS PC
Fields of application
The QVis viscometer can be run either in stand-alone mode or - with the included powerful software - on any WINDOWS computer via RS-232/USB. By means of its analog output (process version) it can also be used to surveil certain viscosity control elements, e.g. for diluent admixing.
Would you like to analyze and control the viscosity of your fluids continuously during your process? The inline viscosimeter QVis 01/o automates your viscosity monitoring and generates measuring results which are reproducible and documentable. Banish flow cups and keep track of your fluid viscosity at all times!
Application
Since measurement of the dynamic viscosity with QVis is completely independent of the direction of flow, the mounting of the QVis 01/o sensor can be realized in any form of pipe, regardless of the flow conditions in it. QVis can be operated in stand-alone mode or it can be connected to your computer; a comfortable pc software is included in the delivery and allows you to automate measuring procedures and to further process the obtained data.
Composition
The inline viscosimeter QVis 01/o consists of only two components: a probe and a compact electronic unit which are connected through a flexible cable. The robust plastic housing includes an electronic control and evaluation system and can be mounted directly on a wall or into your control cabinet.
The measuring head is equipped with a 1″ screw connection and allows maximum mounting flexibility. Depending on your requirements further types (e.g. clamping fastened sensors with screw-cap or sensors with special thread or flange connection) are available upon request. We offer different sensors for different applications: A distinction is made between sensors for electrically conductive and non-conductive fluids as well as for sensors suited for high temperature or high pressure applications. No matter your application, we have the right sensor for you and will be happy to help you find it.
Technical data
|
Power supply |
110-240 V, 50/60 Hz |
|
Energy consumption |
< 10 W |
|
Viscosity range |
1 to 10.000 mPas |
|
Repeatability |
Deviation ± 1% for η > 10 mPas Deviation ± 0,1 mPas for η ≤ 10 mPas |
|
Calibration |
reference oil calibration |
|
Response time |
approx. 15 s |
|
Frequency |
approx. 56 kHz |
|
Shear rate |
approx. 3,5 *105 s-1 |
|
Sensor consumption |
< 100 mW |
|
Temperature range sensor |
-20°C to 120°C (optionally up to 300°C) |
|
Pressure range sensor |
25 bar |
|
Temperature measurement |
PT100 (4-wire technology), +/- 0,1°C |
|
Data communication (computer) |
RS-232 interface |
|
Dimensions electronic unit (LxWxH) |
330 x 290 x 145 mm |
|
Dimensions sensor |
immersion depth 50mm, custom-made sizes available upon request |
For the application in explosive hazardous areas, please refer to the explosive-proof process viscosimeter.
Definition Viscosity
Viscosity describes a property of fluids: a high viscosity signifies a tendency towards a state of thickness or solidness and a low viscosity is attributed to fluids that are thin and flow easily.
The term “viscosity” goes back to the word “viscum” which is latin for mistle. The berries of this plant yield a very sticky and gooey juice which was spread on branches in order to catch birds.
Viscosity is expressed in terms of Pas or mPas.
Typical viscosity values
|
Fluid |
Viscosity in mPas |
|
water (20°C) |
1,00 |
|
grape juice |
2 bis 5 |
|
olive oil |
≈100 |
|
honey |
≈10.000 |
|
asphalt |
≈1011 bis 1016 |
|
lacquer |
≈100 |
|
motor oil (25°C) |
≈100 |
|
motor oil (150°C) |
≈6 |
Viscosity in relation to temperature and pressure
The discrepancy in the viscosity given above for motor oil at different temperatures (25°C and 150°C) is an indication of the fact that the viscosity of a fluid is temperature-related. For most fluids, the rule applies that with an increase of temperature there is a decrease of viscosity. Furthermore, viscosity is also pressure-related. When pressure is increased, viscosity increases as well.
New possiblities. With Qvis.
The QVis 01/o is more than just a sensor for the determination of viscosity. It's an intelligent measuring system that facilitates process management and optimizes customized quality control.
