{"id":20613,"date":"2025-10-31T00:25:51","date_gmt":"2025-10-31T00:25:51","guid":{"rendered":"https:\/\/vibromera.eu\/glossary\/iso-8579-1\/"},"modified":"2026-07-03T10:10:36","modified_gmt":"2026-07-03T10:10:36","slug":"iso-8579-1","status":"publish","type":"glossary","link":"https:\/\/vibromera.eu\/ta\/glossary\/iso-8579-1\/","title":{"rendered":"ISO 8579-1: Acceptance Code for Gear Units \u2014 Test Code for Airborne Sound"},"content":{"rendered":"

ISO 8579-1:2002 \u2014 Acceptance Code for Gear Units \u2014 Part 1: Test Code for Airborne Sound<\/h1>\n\t\t
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\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\"Balanset-1A\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t
<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\tDevices<\/a><\/span>\n\t\t\t\t\t\t\t\t

\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tPortable balancer & Vibration analyzer Balanset-1A<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t
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\u20ac<\/span>1,975.00<\/span> + VAT (\u0baa\u0bca\u0bb0\u0bc1\u0ba8\u0bcd\u0ba4\u0bc1\u0bae\u0bcd \u0b8e\u0ba9\u0bcd\u0bb1\u0bbe\u0bb2\u0bcd)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t<\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a>Add to cart<\/a>\t\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\"Balanset-1A\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t
<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\tParts<\/a><\/span>\n\t\t\t\t\t\t\t\t

\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tVibration sensor<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t
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\u20ac<\/span>90.00<\/span> + VAT (\u0baa\u0bca\u0bb0\u0bc1\u0ba8\u0bcd\u0ba4\u0bc1\u0bae\u0bcd \u0b8e\u0ba9\u0bcd\u0bb1\u0bbe\u0bb2\u0bcd)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t<\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a>Add to cart<\/a>\t\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t
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\n\t\t\t\t\t\t\t\tParts<\/a><\/span>\n\t\t\t\t\t\t\t\t

\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tOptical Sensor (Laser Tachometer)<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t
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\u20ac<\/span>124.00<\/span> + VAT (\u0baa\u0bca\u0bb0\u0bc1\u0ba8\u0bcd\u0ba4\u0bc1\u0bae\u0bcd \u0b8e\u0ba9\u0bcd\u0bb1\u0bbe\u0bb2\u0bcd)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t<\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a>Add to cart<\/a>\t\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t
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<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\tDevices<\/a><\/span>\n\t\t\t\t\t\t\t\t

\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tBalanset-4<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t
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\u20ac<\/span>6,803.00<\/span> + VAT (\u0baa\u0bca\u0bb0\u0bc1\u0ba8\u0bcd\u0ba4\u0bc1\u0bae\u0bcd \u0b8e\u0ba9\u0bcd\u0bb1\u0bbe\u0bb2\u0bcd)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t<\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a>Add to cart<\/a>\t\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>
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\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\"Magnet\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t
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\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tMagnetic Stand Insize-60-kgf<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t
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\u20ac<\/span>46.00<\/span> + VAT (\u0baa\u0bca\u0bb0\u0bc1\u0ba8\u0bcd\u0ba4\u0bc1\u0bae\u0bcd \u0b8e\u0ba9\u0bcd\u0bb1\u0bbe\u0bb2\u0bcd)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t<\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a>Add to cart<\/a>\t\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t
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\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\"Reflective\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t
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\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tReflective tape<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t
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\u20ac<\/span>10.00<\/span> + VAT (\u0baa\u0bca\u0bb0\u0bc1\u0ba8\u0bcd\u0ba4\u0bc1\u0bae\u0bcd \u0b8e\u0ba9\u0bcd\u0bb1\u0bbe\u0bb2\u0bcd)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t<\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a>Add to cart<\/a>\t\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t
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\n\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\"Balanset-1A\t\t\t\t\t\t\t\t\t<\/a>\n\t\t\t\t\t\t\t\t\t
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\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\tDynamic balancer \u201cBalanset-1A\u201d OEM<\/a>\n\n\t\t\t\t\t\t\t\t<\/h4>\n\n\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t
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\u20ac<\/span>1,735.00<\/span> + VAT (\u0baa\u0bca\u0bb0\u0bc1\u0ba8\u0bcd\u0ba4\u0bc1\u0bae\u0bcd \u0b8e\u0ba9\u0bcd\u0bb1\u0bbe\u0bb2\u0bcd)<\/h4><\/div>\n\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t<\/i><\/a>\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t<\/a>Add to cart<\/a>\t\n\t\t\t<\/span>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/section>\n\t\t\n

ISO 8579-1:2002<\/strong> (Acceptance code for gear units \u2014 Part 1: Test code for airborne sound<\/em>) is a specialised standard that lays out a detailed, repeatable procedure for measuring and reporting the airborne noise radiated by an enclosed gear unit. It is an acceptance code<\/em>: its purpose is to let a manufacturer and a customer verify that a new or repaired gearbox meets a contractually agreed acoustic performance level. This sets it apart from vibration analysis<\/a>, which examines structural vibration to detect and diagnose faults. ISO 8579-1 is concerned instead with quantifying the total sound power level<\/strong> of the unit for environmental noise control and occupational-health purposes \u2014 a single, defensible “pass or fail” number rather than a diagnostic spectrum.<\/p>\n

1. \u0ba8\u0bcb\u0b95\u0bcd\u0b95\u0bae\u0bcd \u0bae\u0bb1\u0bcd\u0bb1\u0bc1\u0bae\u0bcd \u0b85\u0bb3\u0bb5\u0bc0\u0b9f\u0bcd\u0b9f\u0bc1 \u0b95\u0bca\u0bb3\u0bcd\u0b95\u0bc8<\/h2>\n

The standard’s scope is the determination of the airborne sound emission \u2014 emission sound pressure levels at specified positions and the sound power level \u2014 of enclosed gear units and gearmotors. Because it functions as an acceptance code, its procedures are written to verify compliance with a pre-agreed acoustic specification between supplier and purchaser. The governing principle is that the sound power level<\/strong> \u2014 an intrinsic property of the source, independent of where you stand \u2014 is calculated from a set of sound pressure level<\/a> measurements taken at multiple, precisely defined points on an imaginary surface that envelops the gearbox. By sampling the pressure all around the unit, the method captures the total radiated sound energy rather than the pressure at any one arbitrary location.<\/p>\n

2. Test Environment and Conditions<\/h2>\n

This part of the standard imposes strict requirements on where and how the test is run, so that the only sound measured is the gearbox itself. The test must take place in an acoustic environment that approximates a free field<\/strong> \u2014 no nearby reflecting surfaces to corrupt the measurement. An anechoic chamber is ideal, though a large open outdoor area can serve. Critically, the background noise from every other source \u2014 including the motor driving the test gearbox \u2014 must be measured separately and must be at least 6 dB lower<\/strong> than the gearbox noise, and preferably more than 10 dB lower. If the background is too loud it contaminates the result and invalidates the test. The gear unit must also run under a specified load and speed, since both dramatically influence the noise generated and the \u0b95\u0bbf\u0baf\u0bb0\u0bcd-mesh \u0b85\u0ba4\u0bbf\u0bb0\u0bcd\u0bb5\u0bc6\u0ba3\u0bcd<\/a> tones that dominate it.<\/p>\n

3. Instrumentation<\/h2>\n

The standard fixes the performance class of the equipment in the measurement chain. It mandates a Type 1 (Class 1) precision Sound Level Meter<\/strong>, microphone and filter set conforming to the relevant IEC standards, ensuring high accuracy and consistency. It also requires a Sound Calibrator<\/strong> of the same precision class, and specifies that the entire system \u2014 microphone, meter and cables \u2014 be calibrated with it both immediately before and immediately after the run of sound measurements. That bracketing calibration<\/a> confirms the instrument’s sensitivity did not drift during the test, which is essential for a valid acceptance result.<\/p>\n

4. Measurement Procedure<\/h2>\n

This is the prescriptive heart of the standard. It requires the definition of a hypothetical measurement surface<\/strong> that completely envelops the gearbox \u2014 typically a rectangular parallelepiped (a box shape) set at a fixed distance, usually 1 metre, from the reference surface of the unit. The standard then specifies the minimum number and exact location of microphone positions on that surface; for a parallelepiped this is commonly a set of nine points<\/strong> covering the four sides, the top and key positions between them. The sound pressure level is recorded at each point while the gearbox runs under the agreed steady-state load and speed. Sampling many points is what allows the sound field to be averaged correctly and accounts for the directionality of the radiated noise.<\/p>\n

5. Calculation of Sound Power Level<\/h2>\n

This section supplies the mathematics that turns raw readings into a result. First, the sound pressure levels \u2014 being logarithmic dB values \u2014 measured at the various microphone positions are logarithmically averaged<\/strong> to give the mean sound pressure level over the whole measurement surface. That mean is then used to compute the sound power level (Lw<\/sub>)<\/strong>, a calculation that brings in the area (S) of the hypothetical measurement surface. The final sound power level is a single figure in dB representing the total acoustic energy radiated by the gearbox. Because it is independent of measurement distance and environment, it is the definitive metric for the acceptance test.<\/p>\n

6. Information to Be Recorded and Reported<\/h2>\n

To keep results unambiguous, comparable and fully traceable, the final section lists everything that must appear in the official test report. Beyond the calculated sound power level itself, this includes:<\/p>\n