New Product Launch: Integrated Low Range Laser Turbidity Meter

New Arrival

Integrated low range laser turbidity meter

What is turbidity

There are many parameters that reflect the quality of drinking water, among which turbidity (abbreviated as turbidity) is one of the most important indicators. Turbidity is a measure of the relative clarity of water. It is the optical property of water, which measures the amount of light scattered by particles in the water when light passes through the water sample. The size of these particulate matter is generally on the order of micrometers and below (for comparison, the diameter of hair strands is about 70 micrometers), and they are called colloids. When the concentration of colloidal substances in water is high, it is easy to cause light scattering, making the water appear turbid and opaque. People find it difficult to perceive water with high turbidity, so turbidity is generally listed as a sensory indicator. The unit of turbidity is NTU. When the water contains 1 mg/L (i.e. mass ratio of one millionth) of silica colloid, it corresponds to 1 NTU.

Measurement significance

The general public only has a vague concept of turbidity and does not have professional instruments to detect it, but they all know that tap water should not be turbid or have visible impurities. In fact, turbidity is simple and easy to measure, and it is also one of the core indicators for measuring the quality of water. It is not only an indicator reflecting the physical properties of drinking water, used to indicate the clarity or turbidity of water, but also an indirect microbial indicator. Turbidity not only reflects the concentration level of microorganisms in water, but also directly affects the sterilization effect on pathogenic microorganisms.

Unclean water may containsterilePathogenic microorganisms such as toxins, Escherichia coli, Cryptosporidium, and Giardia (commonly known as "two worms", belonging to protozoa). Due to the size of these microorganisms being in the micrometer or below range, they are also a component of turbidity. It is generally believed that when the turbidity of water is below 0.3 NTU, the concentration of pathogenic microorganisms will be very low. In addition, disinfection is a necessary technical means to control pathogenic microorganisms in water. When the turbidity of water is below 1NTU, due to the minimal shielding effect of colloidal substances in the water, the sterilization effect and guarantee rate of pathogenic microorganisms are higher during disinfection. Therefore, the turbidity of water is not only a sensory indicator, but also an indirect microbial indicator.

It is precisely because of the scientific understanding of turbidity mentioned above that China's "Sanitary Standards for Drinking Water" (GB5749-2022) and the latest version of the World Health Organization's "Guidelines for Drinking Water Quality" (Fourth Edition) have set the maximum turbidity limit for tap water at 1 NTU. At the same time, major water supply companies have set the turbidity control index value of the factory water at 0.3 NTU or even lower, effectively ensuring the safety of water quality and eliminating the risk of drinking water microorganisms.

The minimum turbidity value that the eyes can generally recognize is about 4 NTU. In other words, as long as the turbidity of water is below 4 NTU, it is "clear". Therefore, the turbidity value of drinking water cannot be judged by the naked eye. The turbidity of water can be easily measured by a turbidity meter. Turbidity meters are divided into two categories: desktop turbidity meters and online turbidity meters. Turbidity meters can detect very low turbidity, usually up to 0.05 NTU or less; The detection sensitivity of the turbidity meter is also very high, and it can respond to even small changes of 0.01 NTU. Therefore, water supply enterprises and their affiliated water plants are equipped with turbidity meters to conduct daily testing of the turbidity of source water, factory water, and section water in the production process, as well as the water at the end of the pipeline network, to ensure that the turbidity value of the water supply meets the standard.

Measuring principle

This laser turbidity meter emits a beam of light with a wavelength of 660 nm through a laser diode, which passes through the water sample. After scattering by particles in the water sample, it is received by a monitor at a 90 ° angle to the beam and coupled to a detection system through optical fibers for analysis. The amount of light detected is proportional to the turbidity of the water sample. Unlike ordinary infrared light sources or tungsten filament light sources, laser turbidity meters produce highly calibrated monochromatic beams that eliminate stray light. Therefore, their sensitivity is 150 times that of ordinary turbidity meters, and they can accurately measure turbidity below 0.1 NTU.

Execution standard:

JJG 880-2006 "National Metrological Verification Regulations for Turbidity Meters"

Industry applications:

Water quality monitoring for waterworks, surface water, drinking water, and ultrafiltration; Monitoring of water quality in municipal pipeline networks.

If you want to learn more about the integrated low range laser turbidity meter, please feel free to contact the sales personnel of Dongyuan Technology.