January 2005Analytical Instrumentation & Environmental Monitoring
It is important to understand that although the term 'free or residual chlorine' is used commonly, chlorine as such, is not present in water. Except at very low pH values, as in very strong acidic conditions, chlorine exists in water as hypochlorous acid or as the hypochlorite ion. In both cases the OCI group is present.
Free or total or 'available' chlorine may be determined by titration or by colorimetric analysis. In the titrimetric procedure, using Tytronics' FPA 414, the free chlorine reacts with KI in acidic conditions to liberate iodine, which is titrated with sodium thiosulfate. This method is more suitable for the determination of higher levels of 'free or available' chlorine as in bleach solutions.
Free chlorine may be measured colorimetrically using the FPA 814 process colorimeter. The most common method is to use the ortho-toluidine method. Both the titrimetric and colorimetric methods obviously require the addition of reagents and hence increase the requirements for maintenance of the analysers.
Total residual chlorine is also measured colorimetrically using the FPA 814. The first step is to obtain the release of the chlorine associated with nitrogen, as in the chloramines, using the reagent DPD to add KI and sodium arsenite, which in turn liberates the chlorine from the amines. Range of measurement of 'total residual chlorine' is normally 0 to 2,5 ppm.
The direct UV measurement, using the FPA 2014 process UV analyser is therefore most attractive as the very minimal of maintenance is required. As mentioned above, the chlorine in an aqueous solution exists as the hypochlorous acid or hypochlorite. The OCI entity exhibits a very strong characteristic absorption band in the UV region. The additional advantage of the FPA 2014 is that the measurement is continuous as the sample flows through a cell and no sample capture is required. Tytronics is represented locally by Protea Automation Solutions.
Analysers for use in high ambient temperature environments
Analytical Instrumentation & Environmental Monitoring
The 993X series of analysers from Ametek Process Industries are now IECEx Zone 2 certified for use in locations with up to 60°C ambient temperature. Built with IP66-rated enclosures and using an integrated cooling system, they can be installed outdoors or in minimally temperature-controlled enclosures, reducing complexity while lowering capital and operating costs.
Read more...The art of precision measurement
Analytical Instrumentation & Environmental Monitoring
To achieve precise, reliable measurement results when scanning component parts, use is frequently made of reference points. In optical measuring processes, these permit the referencing of three-dimensional objects during the digitisation.
Read more...Vibration test system supports international space industry TANDM Technologies
Analytical Instrumentation & Environmental Monitoring
Dragonfly Aerospace has launched EOS SAT-1, one of seven satellites in the world’s first agricultural-focused constellation. With optimisation of resources being a key component for Dragonfly, it called on TANDM to assist in creating and heavily expanding its environmental testing capabilities by providing a vibration test system that allowed it to perform in-house vibration and shock testing.
Read more...Sensor technology for brewing Endress+Hauser South Africa
Analytical Instrumentation & Environmental Monitoring
Brewing is a delicate balance, blending tradition with innovation. Now, modern sensor technology is stepping in to perfect the art of fermentation.
Read more...Loesche gets dirty Loesche South Africa
Analytical Instrumentation & Environmental Monitoring
The world’s attention is on environmental sustainability, and the pressure on countries and companies to demonstrate their commitment to preserving the environment and preventing climate change is at an all-time high. As we confront a multitude of environmental and social challenges, managing waste and maximising landfill diversion can play a key role.
Read more...Water systems with energy savings and sustainability Labotec
Analytical Instrumentation & Environmental Monitoring
ELGA Veolia has relaunched its award-winning PURELAB flex range, with features to reduce the system’s environmental footprint and incorporate some of the latest innovations in water purification technologies. The ecological improvements integrated into the flex range have been made to reduce water and power consumption.
Read more...Keeping an eye on invisible radiation Omniflex Remote Monitoring Specialists
Analytical Instrumentation & Environmental Monitoring
At its peak in 1994, the energy generation capacity of the UK’s nuclear power stations was 12,7 GW across 16 plants. In 2024, the capacity has fallen to around 5 GW, and the number of stations is down to nine. However, this is far from the end of the story as spent nuclear fuel remains radioactive for centuries, and requires rigorous safety processes to safeguard against leaks.
Read more...Technology for water sustainability Endress+Hauser South Africa
Analytical Instrumentation & Environmental Monitoring
The sustainability of surface water is critical for South Africa’s economic development, social well-being and environmental health. Endress+Hauser has a full range of liquid analysis sensors and transmitters to measure important parameters and has an excellent global track record in water and wastewater process plants and various surface and industrial water monitoring sites.
Read more...Reducing water consumption in the cement industry Loesche South Africa
Analytical Instrumentation & Environmental Monitoring
Water is a finite and irreplaceable resource, fundamental to life on earth. LOESCHE’s vision is to enable its customers to produce high-quality cement, without any water consumption.
Read more...Ensuring occupational health and safety in mining
Analytical Instrumentation & Environmental Monitoring
Probe Integrated Mining Technologies (Probe IMT) has partnered with M3SH Technology to offer state-of-the-art environmental monitoring solutions that address these dual requirements.
printer friendly version