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BS ISO 15727:2020 pdf free

BS ISO 15727:2020 pdf free.UV-C devices —  Measurement of the output of a UV-C lamp.
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 15858. UV-C Devices — Safety information — Permissible human exposure
ISO 29464:2017. Cleaning of air and other gases — Terminology
ISO/IEC 17025. General requirements for the competence of testing and calibration laboratories
CIE S 017, International Lighting Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 29464. CIE S 017 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp IEC Electropedia: available at http://www.electropedia.org/
3.1 ultraviolet radiation UV radiation wavelength of the electromagnetic spectrum of radiation from 10 nm to 400 nm
Note ito entry: The range between 100 nm and 400 nm Is commonly subdivided into:
— UV-A:3lSnmto400nrn;
— UV-B: 280 nm to 315 nm;
— UVC(IZ): 200 nm to 280 nm;
4.2 Types of UV-C lamps
4.2.1 General
UV-C lamps are divided into medium pressure UV-C lamps and low pressure UV-C lamps; air disinfection devices usually use low pressure UV-C lamps. The low pressure UV-C lamps are made of liquid mercury or amalgam that controls mercury vapour pressure in the UV-C lamp to provide mercury atoms required for discharge. Mercury atoms produce 253,7 nm UV-C photons through electron bombardment. Figure 1 shows the spectrum of low pressure tJV-C lamps.
4.2.2 Linear UV-C lamps
The most common type of UV-C lamp, linear UV-C lamps can have any length or diameter and are typically characterized by having connectors at both ends or having a connector at a single end, requiring a compatible fixture, as shown in Figure 2 and Figure 3.
4.3.2 MagnetIc ballasts
Magnetic ballasts are used to start the UV-C lamp and may be either standard electromagnetic or energy-efficient electromagnetic. The ballast provides a time-delayed inductive kick with enough voltage to ionize the gas mixture in the tube after which the current through the tube keeps the filaments energized. The starter will cycle until the tube lights up. While the UV-C lamp is on, a preheat ballast is just an inductor which at the main frequency (50 Hz or 60 Hz) has the appropriate impedance to limit the current to the IJV-C lamp to the proper value. Ballasts shall be fairly closely matched to the UV-C lamp in terms of tube wattage, length, and diameter.
4.3.3 Electronic ballasts
Electronic ballasts are basically switching power supplies, which eliminate the large, heavy, ‘iron’ ballast in favour of an integrated high frequency inverter/switcher. Current limiting is then done by a very small Inductor, which has sufficient impedance at the high frequency. Properly designed electronic ballasts are relatively reliable, which depend on the ambient operating temperature, location with respect to the heat produced by the UV-C lamp as well as other factors.
5 Measurement of the output of a UV-C lamp
5.1 Measurement method classification
There are two methods to measure the output of a LJV-C lamp:
1. Measurement of the output of a LJV-C lamp in a darkroom: Tests in laboratory (also known as static darkroom test) are conducted to ensure the accuracy and consistency of the measured results;
2. Measurement of the output of a UV-C lamp in a test chamber: For industrial application, the tests in a test chamber shall take account of the impact of environmental changes in field (such as temperature change and air velocity change). This method is described in Annex B.
5.2 Measurement of the output of a UV-C lamp in a darkroom
5.2.1 Instrument
The cosine correction for radiometers and spectroradiometers is critical to the proper measurement of the UV-C irradiance. The cosine correction shall be confirmed by the following method for each UV-C lamp and ballast combination so that the UV-C lamp measurements are consistent within and between laboratories.BS ISO 15727 pdf download.


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