ISO/TC 43/SC 1
| Project No. | ISO 5136:2003 |
|---|---|
| Title | <div id="MathJax_Message" style="display: none;"></div> <p>ISO 5136 specifies a method for testing ducted fans and other air-moving devices to determine the sound power radiated into an anechoically terminated duct on the inlet and/or outlet side of the equipment.</p> <p>The method is applicable to fans which emit steady, broad-band, narrow-band and discrete-frequency sound and to air temperatures between - 50 °C and + 70 °C. The test duct diameter range is from 0,15 m to 2 m. Test methods for small (<em>d </em>< 0,15 m) and large (<em>d </em>> 2 m) test ducts are described in the informative annexes H and I, respectively.</p> <p>The maximum mean flow velocity at the microphone head for which the method is suitable, depends on the type of microphone shield used, and is as follows:</p> <p>foam ball 15 m/s; nose cone 20 m/s; sampling tube 40 m/s.</p> <p>Above these values the suppression of turbulent pressure fluctuations by the microphone shield may be insufficient.</p> <p>The method described in ISO 5136 is applicable to a sound source in which a fan is connected to ducts on at least one side. It is also applicable to other fan/attenuator combinations or equipment incorporating fans which can be considered as "black boxes".</p> <p>Examples of fans and other equipment covered by ISO 5136 are</p> <p>ducted centrifugal fans, ducted axial flow fans, ducted mixed-flow fans, ducted air-handling units, ducted dust-collection units, ducted air-conditioning units, and ducted furnaces.</p> <p>ISO 5136 is also applicable to other aerodynamic sources such as boxes, dampers and throttle devices provided that a quiet air flow delivered by an auxiliary fan is available, and the signal-to-noise ratio of sound pressures to turbulent pressure fluctuations in the test duct is at least 6 dB.</p> <p>It is not applicable to non-ducted fans or equipment.</p> |
| Registration number (WIID) | 28316 |
| Scope | <div id="MathJax_Message" style="display: none;"></div> <p>ISO 5136 specifies a method for testing ducted fans and other air-moving devices to determine the sound power radiated into an anechoically terminated duct on the inlet and/or outlet side of the equipment.</p> <p>The method is applicable to fans which emit steady, broad-band, narrow-band and discrete-frequency sound and to air temperatures between - 50 °C and + 70 °C. The test duct diameter range is from 0,15 m to 2 m. Test methods for small (<em>d </em>< 0,15 m) and large (<em>d </em>> 2 m) test ducts are described in the informative annexes H and I, respectively.</p> <p>The maximum mean flow velocity at the microphone head for which the method is suitable, depends on the type of microphone shield used, and is as follows:</p> <p>foam ball 15 m/s; nose cone 20 m/s; sampling tube 40 m/s.</p> <p>Above these values the suppression of turbulent pressure fluctuations by the microphone shield may be insufficient.</p> <p>The method described in ISO 5136 is applicable to a sound source in which a fan is connected to ducts on at least one side. It is also applicable to other fan/attenuator combinations or equipment incorporating fans which can be considered as "black boxes".</p> <p>Examples of fans and other equipment covered by ISO 5136 are</p> <p>ducted centrifugal fans, ducted axial flow fans, ducted mixed-flow fans, ducted air-handling units, ducted dust-collection units, ducted air-conditioning units, and ducted furnaces.</p> <p>ISO 5136 is also applicable to other aerodynamic sources such as boxes, dampers and throttle devices provided that a quiet air flow delivered by an auxiliary fan is available, and the signal-to-noise ratio of sound pressures to turbulent pressure fluctuations in the test duct is at least 6 dB.</p> <p>It is not applicable to non-ducted fans or equipment.</p> |
| Status | Standarts spēkā |
| ICS group | 17.140.20 23.120 |