# ASME PTC36-2018 pdf free

**ASME PTC36**-2018 pdf free.Measurement of Industrial Noise Performance Test Codes.

frequency: The rate of change with time of the instantaneous phase of a sine function divided by 2n, with the dimensions of cycles per second or hertz (Hz).

hertz (Hz): see frequency.

level: in acoustics, logarithm of the ratio of a variable quantity to a corresponding reference value of the same units. The base of the logarithm, is assumed to be 10. Unless otherwise specified, the reference value and the kind of level are to be specified. See also ANSI/ASA S1.8.

microphone: electroacoustlc transducer that produces electric signals when excited by acoustic signals. nearfield: the part of the sound source field that lies between the source and the far field. In this region, the sound pressure does not decrease 6 dB for each doubling of distance from the source.

octave band: sound contained within a restricted frequency band where the highest frequency is twice the lowest frequency. Octave and one-third octave (octave band divided into three parts) band measurements are found on acoustical instruments. See also ANSI/ASA S1.6.

reflecting surface: an acoustically non-absorptive (acoustically hard) surface, as opposed to an acoustically absorptive (acoustically soft) surface.

reverberant field: the sound in an enclosed or partially enclosed space that has been reflected repeatedly or continuously from the boundaries.

sound: an oscillation in an elastic medium that can produce the sensation of hearing. Also, the sensation of hearing caused by a pressure oscillation.

sound absorption: reduction in sound energy as It reflects off a surface.

sound level: measured in decibels, a frequency-weighted sound-pressure level obtained using a sound-level meter whose weighting characteristics are specified in ANSI/ASA S1.4/Part 1/IEC 61672-1.

sound-level meter: a device that is used to measure sound-pressure level, functioning in accordance with the standard specifications for sound-level meters established by ANSI/ASA Si .4/Part 1/IEC 61672.1 and filters established by ANSI! ASA Sill/Part 1/IEC 61260-1 (See Section 7).

sound-power level (Lw): ten times the logarithm to the base ten of the ratio of the sound power produced by the sound source to the reference power of 1012 watts (W).

sound-pressure level (L,J: ten times the logarithm to the base ten of the ratio of the square of the sound pressure of the sound under consideration to the square of the standard reference pressure. The standard reference pressure is 20 micropascals (pa) or its equIvalent, 2*10 N/m2.

tone: a sound wave capable of exciting an auditory sensation of pitch (see also discrete frequency).ASME PTC36 pdf download.