NBN EN 60076-10 : 2001

INTRODUCTION
1 Scope
2 Normative references
3 Definitions
4 Instrumentation and calibration
5 Choice of test method
6 Load conditions
   6.1 General
   6.2 No-load current and rated voltage
   6.3 Rated current and short-circuit voltage
   6.4 Reduced-load current
7 Principal radiating surface
   7.1 General
   7.2 Transformers with or without cooling auxiliaries,
        dry-type transformers in enclosures and dry-type
        transformers with cooling auxiliaries inside the
        enclosure
   7.3 Cooling auxiliaries mounted on a separate
        structure spaced >= 3 m away from the principal
        radiating surface of the transformer
   7.4 Dry-type transformers without enclosures
8 Prescribed contour
9 Microphone positions
10 Calculation of the area of the measurement surface
   10.1 Measurements made at 0,3 m from the principal
        radiating surface
   10.2 Measurements made at 2 m from the principal
        radiating surface
   10.3 Measurements made at 1 m from the principal
        radiating surface
   10.4 Measurements on test objects where safety
        clearance considerations require a measurement
        distance which for all or part of the prescribed
        contour(s) exceeds the provisions of 10.1 to
        10.3
11 Sound pressure method
   11.1 Test environment
   11.2 Sound pressure level measurements
   11.3 Calculation of average sound pressure level
12 Sound intensity method
   12.1 Test environment
   12.2 Sound intensity level measurements
   12.3 Calculation of average sound intensity level
13 Calculation of sound power level
14 Addition of no-load and load current sound power
   levels
15 Far-field calculations
16 Presentation of results
Annex A (informative) Narrow-band and time-synchronous
        measurements
Annex B (informative) Typical report of sound level
        determination
Annex ZA (normative) Normative references to
         international publications with their
         corresponding European publications

Describes sound pressure and sound intensity measurement methods by which sound power levels of transformers, reactors and their associated cooling auxiliaries may be determined.