Water quality inspection Water quality inspection

Water quality inspection

Experts often need to analyze the pollution in rivers, oceans, underground water, and other sources of water to determine the cause of environmental deterioration and potential health hazards. So environmental regulators require a reliable, efficient way to measure potential water pollutants using reference values and measurement methods stipulated by law.

 

Hamamatsu provides high-sensitivity optical sensors and high-luminance light sources for water quality inspection equipment that detects pollutant components in trace amounts.

Light-based methods to inspect and measure water quality

Ultraviolet absorption measurement

Dissolved organic molecules commonly exhibit strong absorption in the ultraviolet (UV) range. This method determines organic pollutants present in industrial drainage and river water by measuring the pollutants’ absorbance of UV light.

Total nitrogen measurement

One approach to nitrogen measurement is converting dissolved nitrogen into nitrates. UV absorption spectroscopy (commonly at 220 nm) is a powerful technique for measuring these nitrates.

Total phosphorus measurement

Measuring dissolved phosphorus can be challenging. One common technique is treating the sample through chemical reactions to produce molybdenum blue. Absorption measurements around 880 nm can be correlated to the concentration of phosphorus.

Fluorescence measurement

Oil content and polycyclic aromatic hydrocarbon (PAH) are measured by irradiating ultraviolet light on factory and vessel drainage and measuring the generated fluorescence.

Atomic fluorescence spectrometry (AFS)

Atoms absorb specific wavelengths of light, and the absorbed light is reemitted in the form of fluorescent light. Atomic fluorescence spectrometry is an analysis method that detects this fluorescent light and determines the element. It can measure elements such as mercury with high sensitivity at the parts per trillion (ppt) level.

Atomic absorption spectrometry (AAS)

This analysis method determines the quantity of atoms by irradiating a specific wavelength of light on the sample atomized through thermal dissociation and measuring the absorption spectrum. Because this method is less susceptible to spectral interference, it is used to analyze elements (present as the main or trace components) in various fields.

Recommended products

This is a highly stable lamp module that features high luminance in the ultraviolet region (220/254 nm). It is widely used as a light source for ultraviolet light absorption measurement and fluorescence excitation in place of low-pressure mercury lamps. Because it is compact and driven with a 5 V battery, it can be installed in portable analytical instruments. In addition, a cylindrical OEM type suitable for compact analytical instruments is available.

Si photodiode S12742-254

This is a Si photodiode with a bandpass filter specifically designed for 254 nm light absorption measurement. The sensitivity spectral bandwidth is extremely narrow at 10 nm (typ.), allowing accurate photometry with minimal effects from stray light. In addition, types with a bandpass filter for other wavelengths, such as 220 nm (for nitrogen measurement) and 275 nm (for reference), are available.

Si photodiode S1336-44BQ

This is a TO-5 package type Si photodiode for absorptiometers with sensitivities in the 190 to 1100 nm range.


In addition to this product, a wide lineup is available including TO-8, TO-18, and ceramic packages, as well as types with different spectral response ranges. 

CMOS linear image sensor S11639-01

This is a CMOS linear image sensor with sensitivity in the 200 to 1000 nm range suitable for absorptiometers. In addition to this product, a wide-ranging product lineup is available for different sensitivities, readout speeds, and other parameters. 

Back-thinned type CCD area image sensor S10420-1106-01

This is a back-thinned type CCD area image sensor with sensitivity in the 200 to 1000 nm range suitable for absorptiometers.


In addition to this product, a wide-ranging product lineup is available for different sensitivities, readout speeds, and other parameters. 

Photomultiplier tube R7154

This is a PMT for atomic fluorometers. It features extremely high sensitivity to ultraviolet light and solar-blind characteristics.

Phototube R6800U-01

This is a phototube for atomic absorptiometers that can be used for mercury monitoring. It features sensitivity to ultraviolet light and solar-blind characteristics.

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