Accurate turbidity measurement system and method, using speckle pattern
Provided is an accurate turbidity measurement system and method, using a speckle pattern, in which a speckle pattern may be used for turbidity measurement, thereby enabling turbidity and bacterial or microbial contamination to be measured with high accuracy. The system may include: a measuring container which has a light input part formed in one side thereof, has a light scattering space formed therein, and has a light output part formed in the other side thereof; and an optical dilution member which is formed in at least a portion of the light scattering space, has a sample receiving part formed in one side thereof, and comprises an optical dilution medium having a role of optically diluting a speckle pattern of the sample.
1 . An accurate turbidity measurement system using a speckle pattern, the system comprising:
a measuring container which has a light input part disposed in one side thereof and configured to enable laser light to be inputted, has a light scattering space defined therein and configured to enable multiple reflection or multiple scattering of the laser light through multiple paths, and has a light output part disposed in an other side thereof and configured to enable a measurement of micro-turbidity by using the speckle pattern generated in the light scattering space;
an optical dilution member which is disposed in at least a portion of the light scattering space, has a sample receiving part disposed in one side thereof and configured to receive a sample being measured, and comprises an optical dilution medium configured to dilute the speckle pattern of the sample and enable the measurement of the micro-turbidity of the sample;
a laser source configured to emit the laser light to the light input part;
a first camera configured to photograph the speckle pattern of the light output part; and
a speckle pattern variation calculation part configured to measure a variation over time of the speckle pattern using video information received from the first camera,
wherein the speckle pattern variation calculation part is configured to calculate a micro-turbidity value proportionally by multiplying a measured turbidity value obtained from the variation of the speckle pattern with a multiple of an area of the optical dilution member based on an area of the sample.
2 . The system of claim 1 , wherein the measuring container has an overall cylindrical shape made of at least metal, glass, synthetic resin, and combinations thereof, in which scattering protrusions or scattering layers are defined on an inner surface.
3 . The system of claim 1 , wherein, in the measuring container, a first height of the light input part and a second height of the light output part differ from each other, and a main light-emitting axis of the laser source configured to generate the laser light is deviated from a main light-receiving axis of the first camera configured to measure the speckle pattern, or a first eccentric position of the light input part and a second eccentric position of the light output part differ from each other.
4 . The system of claim 1 , wherein the optical dilution member is a pure light transmission body from which optical foreign matter or biological contamination is completely eliminated, and the speckle pattern is not produced therein.
5 . The system of claim 4 , wherein the optical dilution member has an overall circular cylindrical shape in which at least a portion of the sample receiving part is disposed at a center axis of the measuring container, and the optical dilution member is configured to encompass the sample.
6 . The system of claim 1 , wherein the measuring container has an optical hole defined at a portion that corresponds to a main light-emitting axis line of the laser source passing through the sample, and
wherein the system further comprises:
a second camera configured to photograph brightness of the optical hole; and
a macro-turbidity calculation part configured to calculate macro-turbidity using a brightness information received from the second camera.
7 . An accurate turbidity measurement method using a speckle pattern, the method comprising:
emitting laser light into a measuring container through a light input part;
enabling multiple reflection or multiple scattering of the laser light through multiple paths using a light scattering space of the measuring container, wherein a part of the laser light passes through a sample and exhibits the speckle pattern, and another part of the laser light passes through an optical dilution medium that optically dilutes the speckle pattern of the sample; and
measuring micro-turbidity of the sample by measuring the optically diluted speckle pattern of the sample through a light output part of the measuring container,
wherein, in the measuring the micro-turbidity, the micro-turbidity is calculated proportionally by multiplying a turbidity value obtained from a measured variation of the speckle pattern with a multiple of an area of the optical dilution medium based on an area of the sample.
8 . The method of claim 7 , further comprising: after the enabling multiple reflection or multiple scattering of the laser light, calculating macro-turbidity by measuring brightness of the laser light that has passed through the sample through an optical path of the measuring container.