DI-HFAC-80272A

Machinery and Equipment Pre-Installation Airborne Sound Measurements Test Report

The Machinery and Equipment Pre-Installation Airborne Sound Measurements Test Report describes airborne sound tests and results to demonstrate compliance with MIL-STD-1474.

Approval DateApril 13, 2015

AMSC NumberN9535

Preparing ActivitySH

Project NumberHFAC-2015-007

OPR—

DTIC ApplicableNo

GIDEP ApplicableNo

Limitation—

Applicable Forms—

Approval Limitation—

Form Version—

DID Formatfree_text

963C CompliantYes

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.

Supersedes

DI-HFAC-80272

DI-HFAC-81278

Description & Purpose

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Application & Interrelationship

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Use & Relationship

The Machinery and Equipment Pre-Installation Airborne Sound Measurements Test Report provides a description of the airborne sound tests and results in order to demonstrate compliance with the requirements of MIL-STD-1474.

a. This Data Item Description (DID) contains the format, content, and preparation instructions for that data generated as specified in MIL-STD-1474 and ANSI/ASA S12.67, Pre-Installation Airborne Sound Measurements and Acceptance Criteria of Shipboard Equipment.

b. This DID shall be applied for each machinery and equipment item with an airborne noise requirement, excluding fans, fan-coil units, fan-coil assemblies, air handling units, and other air moving devices when MIL-STD-1474 and ANSI/ASA S12.67 is invoked in the contract specifications or statement of work.

c. The data reported by this DID may be used to support the analysis and design development described in DI-HFAC-81278, Airborne Noise Analysis and Control Design History Booklet.

d. This DID supersedes DI-HFAC-80272.

Preparation Instructions

1Reference documents.The applicable issue of the documents cited herein, including their approval dates and dates of any applicable amendments, notices, and revisions shall be as specified in the contract.

2Format.The Machinery and Equipment Pre-Installation Airborne Sound Measurements Test Report shall be in the Contractor's format.

3Content.The Machinery and Equipment Pre-Installation Airborne Sound Measurements Test Report shall contain the following sections.

3.1Test and equipment information.This section shall contain:

3.1.1Make, model, and serial number of the unit under test, including identification of major components, driver, and driven unit.

3.1.2Ship name(s) and hull number(s) for which the unit is being acquired.

3.1.3Compartment or on-deck location where the unit will be installed.If identical units by make and model number will be installed in any one compartment, identify the specific locations in that compartment where the unit will be installed.

3.1.4Overall unit dimensions and orientation of machinery or equipment item undergoing testing.

3.1.5Evaluating activity and test site, including name, telephone number, and e-mail addresses of the individuals who performed and supervised the tests.

3.1.6Test date.

3.1.7Specified acceptance criteria, including reference units.

3.1.8Driver unit horsepower.

3.1.9Rated electrical characteristics, including volts, amps, and phase.

3.1.10Rated fluid media parameters (e.g., flow rates, temperatures, pressures).

3.1.11Equipment rated operational speeds (e.g., driver and driven unit revolutions per minute (rpm)).

3.1.12Expected equipment primary source excitation frequencies (e.g., rotational frequencies, gear tooth mesh frequencies, motor slot frequency, cylinder firing frequencies, vane frequencies, blade frequencies, piston frequencies, turbocharger frequencies).

3.1.13Resilient mount manufacturer, make, model number, date of manufacture, load range, and natural frequency of resilient mounts used to support the device under test.

3.1.14Number of resilient mounts used.A photo shall be included showing each installed resilient mount.

3.1.15If the use of non-Navy standard resilient mounts has been approved, include the characteristics including load rating in pounds and resonant frequency of the mounts.

3.1.16Operational load (e.g., full, half) of the machinery or equipment undergoing testing.

3.1.17Operating speeds (rpm) used during test.

3.1.18Throttling conditions, if any, and a description of how throttling conditions are set and verified.

3.1.19Operating suction and discharge fluid media parameters during test (e.g., flow rates, pressures, temperatures).

3.1.20Electrical inputs, outputs, or both used during test.

3.1.21Identification of make and model of measurement and analysis instrumentation used, including calibration instrumentation.Certificates of laboratory calibration shall be reported.

3.1.22Details of instrument settings used during the testing, e.g., type of sampling window, coupling, sampling frequency, sampling time, number of averages, averaging type, and frequency resolution of the data, if appropriate.

3.1.23Name and other information identifying any individuals representing the procuring activity who witnessed the test, including e-mail and telephone number.

3.2Drawings, photographs, and calculations.This section shall contain:

3.2.1Identification and arrangement of major components and unit under test.

3.2.2Resilient mount location and orientation, including any sway braces; and overall wet weight and center of gravity of the item undergoing testing with respect to a defined reference position.

3.2.3Calculated load on each resilient mount compared to specified load range of each mount; and calculated natural frequency of each mount when experiencing the calculated load.

3.2.4Drawing and dimensional description of the foundation and/or mounting structure used to support the machinery or equipment item undergoing testing.

3.2.5Arrangement and description of flexible hose assemblies and flexible duct connections showing configuration, diameter and lengths of flexible sections, and details of how the weights of these were supported.Photos shall be included.

3.2.6Arrangement of piping and fittings used to facilitate testing and details of how the weights of these were supported.

3.2.7Arrangement of electrical power leads coupled with arrangements of cables used with instrumentation.

3.2.8Location and orientation of each microphone relative to the envelope of the item under test.

3.2.9Locations and sizes of equipment air inlet and discharge openings.

3.2.10Location of acoustical center of sound source.

3.2.11Acoustical environment (indoor).When testing indoors, the following shall be included:

3.2.11.1Location and orientation of test unit relative to floor, walls, ceiling, and contents of test room.

3.2.11.2Test location (e.g., anechoic, reverberant); dimensions of the test room or chamber; description of the physical treatment on walls, ceiling, and floor.

3.2.11.3Description of any exposed insulating materials installed on the walls, floor, or ceiling including manufacturer, model number, thickness, density, and facing.

3.2.12Acoustical environment (outdoor).When testing outdoors, the following shall be included:

3.2.12.1Location and orientation of test unit relative to buildings, structures or other reflecting surfaces or objects.

3.2.12.2Description of the ground surface, and wind direction and speed.

3.3Measured data.This section shall contain:

3.3.1Measured data in reference units that are identical to the specified reference units.

3.3.2Any measurements that are included in graphical form shall show ordinate (magnitude) values with 10 dB between major divisions.

3.3.3Measured data compared, by measurement location and orientation, with accompanying information at that same location including background and ambient data and assigned limits.

3.3.4For airborne noise levels that exceed the specified limits, excesses shall be clearly indicated in any tabulated and plotted data.

3.3.5If excesses to the specified octave band airborne levels are included in graphical form, plots of narrowband data measured at the offending microphone positions, with frequency resolution not to exceed 1 Hz, shall be included.

3.3.6The report shall identify the mechanisms that exist within the machinery or equipment item that are specifically responsible for the measured excesses (e.g., rotational frequency, blade, vane or piston frequency, firing frequency, gear mesh frequency, coincidence of a forcing frequency with a natural frequency of the mounting system, resonance in the subbase).

References

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