BS ISO 22197-5:2021 pdf download – Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for air-purification performance of semiconducting photocatalytic materials Part 5: Removal of methyl mercaptan
This document specifies a test method for the determination of the air-purification performance of materials that contain a photocatalyst or have photocatalytic films on the surface, usually made from semiconducting metal oxides, such as titanium dioxide or other ceramic materials, by continuous exposure of a test piece to the model air pollutant under irradiation with long‑wave ultraviolet (UV) light. This document is intended for use with different kinds of materials, such as construction materials in flat sheet, board or plate shape, that are the basic forms of materials for various applications.
This document also applies to structured filter materials including honeycomb-form, woven and non-woven fabrics, and to plastic or paper materials if they contain ceramic microcrystals and composites. This document does not apply to powder or granular photocatalytic materials. This test method is usually applicable to photocatalytic materials produced for air purification. This method is not suitable for the determination of other performance attributes of photocatalytic materials, i.e. decomposition of water contaminants, self‑cleaning, antifogging and antibacterial actions. It concerns the removal of methyl mercaptan.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 10677, Fine ceramics (advanced ceramics, advanced technical ceramics)
— Ultraviolet light source for testing semiconducting photocatalytic materials
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
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substance that performs one or more functions based on oxidation and reduction reactions under photoirradiation, including decomposition and removal of air and water contaminants, deodorization,and antibacterial, self‑cleaning and antifogging actions
products such as dimethyl disulphide by some test pieces under the dark condition. Therefore, this document adopts a different dark test condition from that in the other parts of the ISO 22197 series. However, this document cannot be applied to a test piece which does not give a stable concentration of methyl mercaptan in the designated time of test. The photocatalytic activity can depend on physical and chemical properties of pollutants mainly due to the adsorption process involved. For complete evaluation of air purification performance of photocatalytic materials, it is recommended that one or more suitable test methods as provided in other parts of the ISO 22197 series are combined.
6 Apparatus
6.1 Test equipment The test equipment enables a photocatalytic material to be examined for its pollutant‑removal capability by supplying the test gas continuously, while providing photoirradiation to activate the photocatalyst. It is the same as that used in the test method for the removal of nitric oxide (see ISO 22197‑1) and consists of a test gas supply, a photoreactor, a light source and pollutant‑measurement equipment. Since low concentrations of pollutants are to be tested, the system shall be constructed with materials of low absorption and resistant to UV radiation, e.g. acrylic resin, stainless steel, glass and fluorocarbon polymers. An example of a test system is shown in Figure 1. Tests should be carried out in a fume hood with a scrubber or similar ventilation system in order to protect the laboratory personnel from the strong, offensive odour of methyl mercaptan and its reaction products.BS ISO 22197-5 pdf download.