This part of GB 1094 defines sound pressure and sound intensity measurement methods by which sound power levels of transformers, reactors and their associated cooling auxiliaries may be determined.
Note: for the purpose of this standard, the term "transformer" means "transformer or reactor".
The methods are applicable to transformers and reactors covered by the GB 1094 series, GB/T 10229, GB 6450 and GB/T 18494 series, without limitation as regards size or voltage and when fitted with their normal cooling auxiliaries.
This standard is primarily intended to apply to measurements made at the factory. Conditions on-site may be very different because of the proximity of objects, including other trans- formers. Nevertheless, the same general rules as are given in this standard may be followed when on-site measurements are made.
Foreword I
Introduction III
1 Scope
2 Normative References
3 Terms and Definitions
4 Instrumentation and Calibration
5 Choice of Test Method
6 Load Conditions
7 Principal Radiating Surface
8 Prescribed Contour
9 Microphone Positions
10 Calculation of the Area of the Measurement Surface
11 Sound Pressure Method
12 Sound Intensity Method
13 Calculation of Sound Power Level
14 Addition of No-load and Load Current Sound Power Levels
15 Far Field Calculation
16 Presentation of Results
Appendix A (Informative) Narrow-band and Time-synchronous Measurements
Appendix B (Informative) Typical Report of Sound Level Determination
