Industrial Gases Industry


CARBOSCAN 300 is a turnkey, factory-calibrated system for the online process monitoring of CO2 gas which ensures end-to-end quality assurance. The system uses the method of optical absorption spectroscopy to identify contaminants: it can identify even the tiniest traces of contaminants (down to sub PPB levels) using the light attenuation that these cause in the gas.


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CO2 - possible uses

CO2 – This odorless and colorless gas is produced by the combustion of hydrocarbon-containing substances, fermentation, the production of fertilizer and other chemical processes. Instead of allowing it to dissipate unused into the atmosphere, it is filtered, purified and supplied in special tanker trucks for reuse in industry, where it is used as a natural refrigerant or to carbonate drinks. Depending on what it is used for, the gas must satisfy different purity requirements. In order to ensure a consistent and high standard of quality, monitoring at both the gas supplier and at the consumer is needed.

Reliably identifying contaminants

One of the biggest consumers of CO2 is the beverage industry. Operators of beverage bottling plants require the purified gas to carbonate drinks. It goes without saying, of course, that these applications have extremely high requirements in terms of purity. Complex gas analyses and the evaluation of measurements are not part of the drinks bottling company's core business, however. This is where a reliable quality assurance system comes in. With CARBOSCAN 300, UNISENSOR has a turnkey, pre-configured and factory-calibrated system that is supplied in a steel container complete with all related equipment. It is installed on pre-prepared foundations and can be operational in no time thanks to the pre-configured components. No recalibration is required.

The system takes care of the precise and fully automatic online process monitoring of CO2. It can be tailored entirely to customers' requirements and offers highest reliability, extending as far as certification of the required gas quality. A relational database stores all the data recorded over a period of at least two years, so that operators of beverage bottling plants can trace the quality of every bottle over the entire shelf life of the drink it contains.

Optical absorption spectroscopy

CARBOSCAN 300 operates according the principle of optical absorption spectroscopy. This technology involves an electromagnetic beam hitting a sensor unit after having been split through a grid and directed through the gas being analyzed.

Two broadband spectrometer modules are used to selectively detect various contaminants. Since different substances cause different light attenuations in the gas, they can be uniquely identified using the spectrum, i.e. their physical fingerprint. Sum parameters can also be displayed.

Selective detection of more than 40 contaminants

CARBOSCAN 300 can currently selectively detect more than 40 different contaminants based on the light attenuation they cause. These include hydrocarbons of acetaldehyde, acetylene, from ethane and ethanol to methanol, propane and propylene, sulfur compounds, aromatic hydrocarbons and other components such as ammonia, NOX and water. If necessary, other components can be added at any time. The system satisfies the quality requirements of the ISBT (International Society of Beverage Technologists) and EIGA (European Industrial Gases Association).

Detection limits in the ppb range

Contaminants can be detected reliably down to sub ppb levels. The system can detect traces of benzene as low as 3 ppb. By way of illustration, this is the same degree of accuracy as if it were to reliably find and identify three people out of the entire population of China.


CARBOSCAN Compact 300 is pre-configured in an air-conditioned steel container in accordance with the client's specifications and supplied with all related equipment. It comprises multiple components:

  • At its core is the Process Analyzer cabinet, which measures the gas components.
  • The Truck Control system with evaporator is attached to the exterior of the container and is used to monitor the incoming supply of CO2 gas.
  • The Gas Multiplexer, with up to eight inputs and downstream sampling preparation system, allows various measuring points to be connected at various stages in the process.

A VISU Station is optionally available for the convenient monitoring of the system. This can be connected via the network to the Process Analyzer and conveniently displays all of the recorded data and evaluations.

For gas suppliers, a Certification Module is also optionally available that allows a certificate to be created and printed out at the press of a button following successful measurement.

No calibration errors

The system is calibrated at the factory, does not require calibration gas, fuel gas or zero air and does not need to be recalibrated by the operator. Automatic reference measurements, carried out at short intervals, safeguard measurement stability. As a result, there are no operating costs associated with the laborious task of bottle handling when exchanging calibration gas bottles as is usually the case with conventional systems. Operating and calibration errors by the operator are also excluded, eliminating downtime.

Areas of use

Operators of beverage bottling plants require CO2 to carbonate their beverages. They need to ensure that the CO2 they use is not contaminated with impurities that could affect the quality of the finished beverage. CARBOSCAN 300 offers reliable brand protection and therefore also safety for consumers.

Even breweries, which produce CO2 as a waste product, can only use it in food and beverages if they can guarantee it does not contain any by-products from the brewing process, such as sulfur compounds, acetaldehyde and ethanol.

Gas suppliers can themselves only sell CO2 if the client's specifications are met.

CARBOSCAN 300, with its sensitive and selective online process monitoring, safeguards continuous quality throughout the production process. Once installed, the turnkey system delivers reliable measuring results for years, providing suppliers and consumers with end-to-end quality and supply chain protection from costly quality incidents.

The quality assurance system is based on optical absorption spectroscopy and can currently identify more than 40 different contaminants. Further contaminants can be integrated via remote connection at any time. The system is pre-configured and calibrated at the factory and does not require any recalibration by the operator. It is ready for use after a very short commissioning process and runs with complete reliability thanks to automatic reference measurements. Conventional systems that use calibration gases, fuel gases and zero air require additional maintenance as a result of the laborious task of gas bottle handling, and are prone to calibration errors by the operator.

The advantages of CARBOSCAN 300:

High accuracy:

The identification of contamination via absorption spectroscopy is highly precise thanks to two broadband spectrometer modules.

Online process monitoring:

The CO2 quality assurance takes place online in the process and if necessary at different measuring points.

Readiness for the future:

The library of contaminants can be extended via remote connection at any time without any need for additional investments in hardware.

Data security:

All recorded data is stored in a relational database for at least two years and can be traced if required.

Calibrated and pre-configured:

The system is pre-configured and calibrated at the factory in accordance with the client's specifications. No recalibration by the operator is required.

Tested quality:

All components have been tested at the factory and are ready for immediate on site use.

Turnkey solution:

The system is supplied as a complete package in an air-conditioned container complete with all related equipment.

Service quality:

A teleservice interface enables trained and skilled UNISENSOR staff to change parameters and carry out fault diagnoses via a secure remote connection.

ContaminantsDetection limits
Acetaldehyde 0,03 ppm
Ammonia 0,5 ppm
Carbon monoxide 0,5 ppm
Phosphine 0,07 ppm
Oxygen (optional 1,0 ppm)
Moisture (optional 1,0 ppm)


ContaminantsDetection limits
Ethene 1,0 ppm
Ethylene 1,0 ppm
Ethanol 1,0 ppm
Methane 1,0 ppm
Methanol 1,0 ppm
n-Butane 1,0 ppm
Ethylacetat 1,0 ppm
Isoamylacetat 1,0 ppm
Dimethylether 1,0 ppm
Propane 1,0 ppm
Propylene 1,0 ppm
Total of volatile hydrocarbons 4,0 ppm


ContaminantsDetection limits
Benzene 0,004 ppm
Toluene 0,004 ppm
Xylene (Ethylbenzene) 0,004 ppm
Total BTX 0,009 ppm


ContaminantsDetection limits
Carbonyl sulfide 0,015 ppm
Hydrogene sulfide 0,02 ppm
Propylmercaptane 0,02 ppm
Sulfur dioxide 0,15 ppm
Total sulfur (H2S, COS, SO2) 0,04 ppm


ContaminantsDetection limits
Nitric monoxide 0,4 ppm
Nitric dioxide 0,5 ppm
NOX (NO, NO2) 0,7 ppm

Further components are available on request.