TOC Analysers for IECEx and ATEX zones

Total Organic Carbon analysers are commonly used to measure the level of organic contamination in water. Online TOC analysers installed in refineries and petrochemical plants are located right in the middle of the process facilities.

Picture of a Technician working on a TOC Analyser

Technician working on a TOC Analyser

Picture of a XY and a loop injection system

Close up picture of the XY and loop injection systems

Picture of a total organic carbon analyser in an ex-zone housing

Total organic carbon analyser QuickTOCultra in an ex-zone housing

Total Organic Carbon analysers are commonly used to measure the level of organic contamination in water. Online TOC analysers installed in refineries and petrochemical plants are located right in the middle of the process facilities. Here explosive gasses, vapours or mist can be present. It is a high risk situation, as any spark or any heat source may cause an explosion. Hence, explosive areas necessitate safety protection measures in order to ensure high labor safety as well as operational safety.

LAR Process Analysers, Germany, offers with its online TOC analysers QuickTOCultra and QuickTOCpurity stand-alone measuring equipment with explosion-proof housings certified according to the latest ATEX and IECEx standards (EN 60079-2:2011-11 and IEC 60079-14:2007). LAR's custom-fit analysers come with stainless steel housings with over pressure encapsulation and purging system (Ex p) that do not require air-conditioned shelters, providing an easier way to maintain and operate the measurement systems. LAR’s stand-alone TOC analysers correspond to requirements of ATEX Zone 1 and Zone 2 (T3/T4) as well as in IECEx Zone 1 T4.

Application-specific injection system

Depending on the water to be tested, LAR offers custom-fit analysers for every measurement task. The QuickTOCpurity is especially designed for pure water applications (steam/ condensate return, boiler feed water, cooling water). The analyser is equipped with a closed injection loop where a subset of a water sample is injected into the furnace. Thus, contamination of the sample by substances in the ambient air is avoided. In addition, VOC and POC (volatile/purgeable organic carbon) are not released and hence, are included in the measurement. The process control of the TOC system is an advantage, especially in chemical and petrochemical plants, in which various substances can be present in the air.

LAR’s QuickTOCultra is designed for complex water compositions. The measurement system is equipped with a robotic, horizontally and vertically moving injection needle that imitates the laboratory injection process. The injection system is capable of transporting and measuring a high content of solid matter without any filtration of the sample. The QuickTOCultra easily handles sticky, fatty, salty, and high-particle samples unlike other TOC analysers.

Ultra high temperature combustion

The furnace is the centerpiece of LAR’s TOC analysers. They use the patented high-temperature combustion method at 1200°C guaranteeing the complete digestion of all carbon compounds in the sample to CO2. Oxidation promoting catalysts, such as those used in other measuring methods, are unnecessary. As a consequence, the operating costs of the measurement system are minimized. Downstream of the furnace, the formed CO2 will be measured by a NDIR detector resulting in the exact determination of TOC. LAR's analysers determine the TOC in less than three minutes and thus, allows the operators to take fast countermeasures in case of water pollution.

Both TOC analysers are designed for the measurement of up to six sample streams in one device. Each sample stream can have different combinations of parameter such as TOC, TC, TIC, COD and/or TNb. Various process streams can so easily be monitored in a single analyser. The TOC analysers are controlled via a 10.4“ touchscreen display. Access to the measuring system can even be done via internet protocol for example from a control room.

LAR’s custom-fitted TOC analysers take care of the concrete challenges of pure water and waste water applications minimizing maintenance efforts and making the optimization and control of complex processes possible.


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The total organic carbon (TOC) is one of the most important sum parameters in the assessment of the organic pollution of water. Since it includes all carbon compounds as one mass, it is exactly defined and an absolute quantity. Therefore, it may be determined directly.

Read more about TOC measurement methods.

Total organic carbon analyzers of LAR Process Analysers AG

The chemical oxygen demand (COD) indicates the amount of oxygen which is needed for the oxidation of all organic substances in water and is thus an important indicator for water analysis. It is considered in the planning and controlling of treatment, as well as assessing its efficiency, thus forming the basis for the calculation of waste water charges.

The COD can be determined in laboratory or online, whereby these methods significantly differ in duration and consumables used.

Read more about COD measurement methods.

COD analyzers of LAR Process Analysers AG

The biochemical oxygen demand (BOD) indicates the amount of oxygen which is needed for the biological degradation of organic substances in water.

Since the generally used BOD5 excludes the nitrification part of the process, this parameter is poorly suited for the control of waste water treatment plants. Alternatively, the total BOD is well-suited, due to the determination of the nitrogen as well as the carbonaceous part of biological degradation.

Read more about the online measurement of BOD.

Toxicity is described as the direct harmful effect of a substance on organisms. These effects can already occur at low concentraions of toxic substances and are dependent on the incubation period and the dosage.

Some test methods that are available on the market can detect toxicity by using fish, daphnia, molluscs, algae or luminous bacteria and testing whether a water sample has a toxic effect on the organisms. They do not, however, identify exactly which toxins are present.

Read more about online toxicity measurements.

BOD / toxicity analyzers of LAR Process Analysers AG

The total nitrogen bound (TNb) shows the pollution of water caused by nitrogen compounds. Nitrogen may be present as ammonia, ammonium salts, nitrites, nitrates and organic nitrogen compounds.

In contrast to single measurements of the above-mentioned components, the TNb determination contains all these substances in a single analysis process.

Read more about online TNb measurements.

The total phosphorus (TP) is a sum parameter that shows the organic and inorganic phosphorus compounds in water. Phosphorus is an essential nutrient for humans as well as flora and fauna. However, the substance – depending on its concentration– may cause serious damage.

Read more about online TP measurements.

TN TP analyzer of LAR Process Analysers AG