Headspace Gas Analyzers

The importance of headspace gas analysis for quality control in Modified Atmosphere Packaging (MAP)

In packaging terms, the headspace refers to the internal volume of a package that is not occupied by the product. The atmosphere in this space is termed the headspace gas. Headspace analysis is the measurement of this headspace gas. Headspace gas analysis is a key part of the quality control process for the food, beverage and pharmaceutical industries for products that have been packaged in a modified atmosphere.

Headspace analysis ensures that the residual oxygen within the headspace gas does not exceed certain defined limits: excessive oxygen within the headspace can result in the growth and proliferation of microorganisms such as bacteria or moulds, which causes spoilage and results in a lower shelf-life of the product. Headspace analysis usually focuses primarily on oxygen measurements, but in many cases CO2 measurement is also important.

How does headspace analysis work?

To carry out headspace analysis, packages are removed from the production line for testing. A thin needle is inserted into the package and a pump draws a small sample of precise volume of headspace gas into the analyzer equipment. The headspace gas comes into contact with a sensor that can measure the concentration of residual oxygen or carbon dioxide in the headspace gas sample.

The headspace analysis equipment – the headspace gas analyzer – provides a reading of the concentration of the gas that is being measured. In cases where products are coming off a line very rapidly, the speed at which headspace analysis can be carried out can be an important factor. In these situations it is much more efficient for an operator to be able to carry out a headspace gas analysis on a sample in, say, five seconds than in 30.

For certain products in transparent foil containers, it may be possible to use an optical oxygen detector to carry out headspace analysis in a non-invasive way.

Dansensor’s testing equipment for headspace analysis to ensure MAP product quality

Dansensor offers a range of different solutions for headspace analysis of MAP products across all relevant industries and sectors:

CheckPoint is a handheld headspace gas analyzer. It is the perfect entry-level product that meets the basic requirements for residual oxygen and optionally CO2 measurements for headspace analysis. It is battery-operated, either with standard AA batteries, or rechargeable batteries.

CheckPoint II represents an advance on CheckPoint and is a portable quality control instrument for headspace analysis. It gives QC managers a tool to ensure that all important data of the MAP production are easily stored on a PC. An optional barcode reader is available for easy product selection and alarm setting.

CheckMate 3 is ideal for larger production facilities and customers with a demand for high accuracy quality control. With CheckMate 3 it is possible to set up a complete workflow for headspace analysis of packages, bottles and pharmaceutical products. It has an easy-to-use barcode option that enables the collection of vital data such as batch number, packaging line, package type and the operator’s name, and is available with a high accurracy Zirconia sensor for oxygen measurements down to ppm range.

OpTech-O2 Platinum gives the operator the ability to measure oxygen in a non-invasive manner through a transparent foil.

Headspace analysis in MAP packaging with high carbon dioxide concentrations

As well as residual oxygen measurements for headspace gas analysis, Checkpoint, Checkpoint II and CheckMate 3 can also have the option to test for both O2 and CO2, to improve quality control by ensuring that the headspace gas mixture is correct. In some circumstances carbon dioxide can affect the oxygen content measurement in instruments that use an electrochemical oxygen sensor (CheckPoint and CheckPoint II for example). Where there is a CO2 content of between 25% and 65% in the headspace gas mixture, Dansensor recommends CheckPoint II O2/CO2, which has a sensor specially designed for such environments. Headspace analysis carried out with CheckPoint II O2/CO2 is able to compensate for the relatively high CO2 levels, thus delivering a more accurate reading for oxygen concentrations. To our knowledge this feature is not available for any other portable headspace analysis instrument on the market.

In situations where the CO2 content exceeds 65% and a high accuracy measurement of headspace oxygen is needed, Dansensor suggests the CheckMate 3 with a Zirconia oxygen sensor. Here, the headspace analysis sensor is not affected by the CO2 content.

In summary

In seeking to advance sensing technology, Dansensor has developed equipment for MAP headspace gas analysis for every application:

  • accurate residual O2 headspace gas analysis
  • O2 headspace gas analysis in the presence of high CO2
  • robust, portable headspace gas analyzers
  • dedicated O2/CO2 headspace gas analyzers
  • MAP audit applications
  • MAP quality control

For further information about any of these headspace analysis products, please visit the relevant web page on the menu on the left, or contact Dansensor: details provided on the Contacts page on the menu bar above.


                          Check Point III 

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