Turbidity Meter
Turbidity meter: An indispensable module for Anton Paar’s laboratory measuring and analysis systems. The reliable turbidity meter measures the turbidity of all types of liquids, particularly beer and beer mixtures. The turbidity meter uses the reliable ratiometric procedure.
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Modules
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HazeQC ME is a turbidity meter which determines the turbidity (haze) by employing a three-angle measurement (0° ...
Sample Changers
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The modular sample changer Xsample 122 automatically fills your samples from the vial into Anton Paar's newest ... -
The Xsample 510 sample changer for packages provides fully automatic sampling out of closed bottles and cans with no ...
The turbidity meter from Anton Paar uses the approved ratio method with measurement at three angles (transmission 0°, scattered light at 25° and 90°) to calculate the turbidity value. The measurement is carried out at a wavelength of 650 nm.
The turbidity meter from Anton Paar has a modular concept
The turbidity meter from Anton Paar can be integrated into existing measuring systems with a Generation M master instrument or an Alcolyzer Plus because a flow-through measuring cell is used. This enables fully automatic filling and measurement when using sample changers. The master instrument controls the whole system, including the turbidity meter.
Turbidity meter from Anton Paar – all parameters at once
The combination of the turbidity meter with PBA-B (Packaged Beverage Analyzer for Beer) determines CO2, alcohol, density, pH, beer color and turbidity in one measuring cycle without sample preparation directly out of the bottle or can.
Call now to learn more about our new turbidity meter!
Anton Paar’s turbidity meter– easy, flexible, reliable.
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The role of turbidity measurement in beer production with the chief character HazeQC ME
Turbidity in liquids
Turbidity or Haze is defined in the DIN EN 27027 standard as follows:
"Turbidity is the decrease in the transparency of a liquid caused by the presence of undissolved substances."
Therefore, turbidity is not a simple physical quantity like density, temperature or weight.
It is based on the effect of light scattering by particles, whose size is in the same order of magnitude as the incident light.
Light scattering means that if a light beam passes near a small particle its direction is slightly changed (the light beam is "bent"). Therefore, the optical picture we get through a turbid sample, seems to be blurry, the sharp edges disappear.
A simple turbidity measurement would be to put a scale with different sized letters behind the sample cuvette and check which is the smallest letter that can be read.
Be aware that turbidity has nothing to do with the color of a liquid! To illustrate: the same yellow beer can be clear or cloudy (turbid).
To make it clearer: Imagine you try to read a newspaper behind a glass of beer: In both cases the letters will look yellow, but in the case of clear beer you will be able to read the words. With turbid beer, the letters will be too blurry and diffuse to be read!
Two beers: Same color - Different turbidity
Turbidity in beer
In beer, there are mainly two types of particles that create turbidity: yeast cells and protein colloids. So in beer we can differentiate between "yeast turbidity" and "colloidal turbidity".
Yeast cells are about 5 - 10 µm in diameter and therefore much bigger than protein colloids (< 1µm).
Get to know HazeQC ME
HazeQC ME is a measuring module for Anton Paar systems to determine the turbidity of liquids.
It measures light at three angles: 0° transmission, 25° and 90° scattered light.
The wavelength of the incident light is 650 nm (red light).
It complies with the MEBAK (Mitteleuropäische Brautechnische Analysenkommision) and the EBC (European Brewery Convention) standards.
The measuring cell is temperature-controlled with a Peltier element.
How does HazeQC ME work?
A red light beam (650 nm) enters the sample cuvette. Three detectors measure an intensity signal at three angles: 0°, 25° and 90° of the incident light beam.
Measuring principle of HazeQC ME
Out of these signals, various turbidity values are calculated.
The measuring cell is temperature-controlled and the measuring temperature can be set in a range of -5 to +40°C.
Ratio method
As the Absorbance (color) of a sample also affects the 90° and 25° detector signals, the absorbance at 0° also has to be measured and taken into account.
Therefore, the absorbance can be compensated and the result is really a turbidity and not a mixture of turbidity and color!
For this reason, the results are always ratios of the scattered light and the transmission (0°). This principle is called the "Ratio Method".
Influence of particle size
The scattering effect of light is stronger if the particle size is similar to the wavelength of the light.
As very small particles (in the range of 650 nm in diameter) will result in a strong scattering, the 90° sensor will detect more intensity.
Bigger particles (like yeast cells with 10 µm diameter) will not "bend" the light beam as strongly and therefore the forward-scattering detector signal at 25° will increase.
Small particles: 90° scattering increases
Big particles: 25° scattering increases
The influence of particle size
In the past, turbidity was measured using the Jackson candle turbidimeter. To do this the sample was poured into a calibrated tube. When the flame of a candle under the bottom of this tube disappeared from view, a visual method was used to read off the turbidity. Turbidity units from the Jackson candle turbidimeter were given as JTU (Jackson Turbidity Units). The Jackson candle turbidimeter was traditionally calibrated using suspensions of kaolin (a fine clay). Now this instrument is no longer in standard use as it cannot directly measure very low turbidities.
Today there are much more accurate and modern electronic turbidity meters available and the turbidity unit JTU has been replaced by NTU (Nephelometric Turbidity Unit), EBC, ASBC or Helms.
