Nitrogen oxide depletion

Nitrogen oxide depletion: Standardized and straightforward measurement

Setting up a measuring station for standardised test engineering is often associated with high logistics and apparatus costs. Numerous single components have to be combined and tested in order to function reliably and in accordance with regulations as an ensemble. Especially in the field of photocatalytic measuring technology, Fraunhofer IST has recently started offering complete turnkey solutions to its customers.

Growing demand for photocatalysis products

Photocatalysis is one of the enabling technologies of the 21st century, with a wide variety of products that can be improved in a fast-growing market, preferably through the use of new catalysts and adapted application methods. A current BCC Research study (BCC Research Advanced Materials Report: Photocatalysts: Technologies and Global Markets 03/2010) estimates the worldwide sales of photocatalyst-based products for 2014 at nearly EUR 1.3 billion with an annual growth rate of 14 %. At the same time, the Association of German Engineers (VDI) estimates the market potential in the next two decades at several 10 billion US dollars (VDI Technology Centre: Future Technologies Update 01/06). Over 80 % of global sales will be accounted for by building products with growth-impeding, self-cleaning and air purification properties. Examples include road surfaces, pavement, noise control walls, tunnels or interior and exterior building façades.

Photocatalytic air purification at Fraunhofer IST

ISO 22197-1 has proven itself as the leading test standard for evaluating the performance of active photocatalytic products in the field of air purification. These test methods are based on measuring the depletion of carbon monoxide (NO) by activating a specimen placed in a photoreactor that has NO flowing through it with UV radiation and determining its air purification capability according to the net amount of nitrogen oxide that is removed. The test and zero gas supply, harmful substance analyser and the light source, wavelength and irradiation intensity are defined along with the arrangement of the specimen in the photoreactor and the photoreactor itself.

Fraunhofer IST has developed a flatbed reactor with a modular structure, supporting the standardised measurement of specimens with dimensions up to 200x100x20 mm (WxDxH) while defining the settings for and continuously measuring key influencing factors such as the irradition intensity, gas flow, temperature and relative humidity, both in the periphery and in the reactor itself. Fraunhofer IST is also looking ahead to the use of the latest LED technology and currently meets all requirements for the future CEN specification for irradiation conditions to test photocatalytic properties (CEN/TS 16599).

What we offer

Fraunhofer IST offers a complete turnkey solution for the standardised measurement of NO depletion. First a comprehensive installation plan is prepared under consideration of the customer’s special requirements. All required components are selected, procured and their functionality tested in Fraunhofer IST laboratories. Then the entire measuring station is transferred to the customer and goes through a technical acceptance procedure.


This article is part of the annual report 2013.


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