| 1:3 Octave Band Filters |
Single 1:1 Octave bands divided into three parts. |
| 1:1 Octave Band Filters |
A division of the frequency range into bands, the upper frequency limit of each band being twice the lower frequency limit. |
| A Weighting |
A standard weighting of the audible frequencies designed to reflect the response of the human ear to noise. |
| Acoustic Calibrator |
An instrument that provides a reference noise source that is used to calibrate and check the performance of a Sound Level Meter. |
| Broadband |
Noise Measurements using parameters which include all the audible noise, such as dB(A) and dB(C) |
| C Weighting |
A standard weighting of the audible frequencies used for the measurement of Peak Sound Pressure level. |
| CE Marking |
A label used to show that the Sound Level Meter conforms to the specification of a European Directive |
| Data Logging |
Measurements can be stored in the Sound Level Meter for download to a PC |
| dB(A) |
Decibels A weighted |
| dB(C) |
Decibels C Weighted |
| dB(Z) |
Decibels Z weighted |
| Decibel (dB) |
The units of sound level and noise exposure measurement |
|
DIN 45641
|
German Standard which defines the additional measurements LAFTeq & LIeqT |
| % Dose |
The noise exposure expressed as a percentage (%) of a fixed level for 8 hours |
| Exposure |
Noise Exposure in Pa2h (Pascal Squared Hours) |
| Fast Time Weighting |
A standard time weighting applied by the Sound Level Meter |
| IEC 60804:1984 |
The International Standard for Integrating & Integrating-Averaging Sound Level Meters |
| IEC 61672:2002 |
The International standard for Sound Level Meter and Integrating Averaging Sound Level Meters has superseded both IEC 60651 and IEC 60804 |
| IEC 60651:1979 |
The International Standard for Sound Level Meters |
| IEC 61260:1995 |
The International Standard for 1:1 Octave & 1:3 Octave Band Filters |
| Impulse Time Weighting |
A standard time weighting applied by the Sound Level Meter |
| Integrating Averaging Sound Level Meter |
A Sound Level Meter which accumulates the total sound energy over a measurement period and calculates an average |
| LA10 |
The noise level exceeded for 10% of the measurement period with 'A' frequency weighting calculated by statistical analysis |
| LA90 |
The noise level exceeded for 90% of the measurement period with 'A' frequency weighting calculated by statistical analysis |
| LAE |
Sound Exposure Level (SEL) with 'A' frequency weighting |
| LAeq,t |
Equivalent continuous sound pressure level. A measure of the average sound pressure level during a period of time, t, in dB with 'A' weighting. |
| LAF |
Sound level with 'A' Frequency weighting and Fast Time weighting |
| LAFmax |
The maximum Sound level with 'A' Frequency weighting and Fast Time weighting |
| LAFTeq |
Takt maximal sound level as defined by DIN 45641 |
| LAI |
Sound level with 'A' Frequency weighting and Impulse Time weighting |
| LAImax |
The maximum Sound level with 'A' Frequency weighting and Impulse Time weighting |
| LAS |
Sound level with 'A' Frequency weighting and Slow Time weighting |
| LASmax |
The maximum Sound level with 'A' Frequency weighting and Slow Time weighting |
| LCE |
Sound Exposure Level (SEL) with 'C' frequency weighting |
| Lceq,t |
Equivalent continuous sound pressure level. A measure of the average sound pressure level during a period of time, t, in dB with 'C' weighting. |
| LCF |
Sound level with 'C' Frequency weighting and Fast Time weighting |
| LCFmax |
The maximum Sound level with 'C' Frequency weighting and Fast Time weighting |
| LCI |
Sound level with 'C' Frequency weighting and Impulse Time weighting |
| LCImax |
The maximum Sound level with 'C' Frequency weighting and Impulse Time weighting |
| LCpeak |
Peak Sound pressure level with 'C' frequency weighting |
| LCS |
Sound level with 'C' Frequency weighting and Slow Time weighting |
| LCSmax |
The maximum Sound level with 'C' Frequency weighting and Slow Time weighting |
| LEP,d |
Daily personal noise exposure |
| Leq |
Equivalent continuous sound pressure level. A measure of the average sound pressure level during a period of time, t, in dB |
| LIeqT |
Impulse weighted Leq,t as defined by DIN 45641 |
| Ln |
Statistical analysis of noise levels. The n denotes the percentage exceedence. |
| LZE |
Sound Exposure Level (SEL) with 'Z' frequency weighting |
| LZeq,t |
Equivalent continuous sound pressure level. A measure of the average sound pressure level during a period of time, t, in dB with 'Z' weighting. |
| LZF |
Sound level with 'Z' Frequency weighting and Fast Time weighting |
| LZFmax |
The maximum Sound level with 'Z' Frequency weighting and Fast Time weighting |
| LZI |
Sound level with 'Z' Frequency weighting and Impulse Time weighting |
| LZImax |
The maximum Sound level with 'Z' Frequency weighting and Impulse Time weighting |
| LZS |
Sound level with 'Z' Frequency weighting and Slow Time weighting |
| LZSmax |
The maximum Sound level with 'Z' Frequency weighting and Slow Time weighting |
| Overload |
The input to the Sound Level Meter is too high for the current measurement range. Change the range |
| Peak |
The maximum value reached by the sound pressure at any instant during a measurement period (in dB usually with C frequency weighting) |
| SEL |
Sound Exposure Level, displayed as LAE, LCE or LZE |
| Slow Time Weighting |
A standard time weighting applied by the Sound Level Meter |
| Sound Level |
Sound Pressure Level with a Frequency weighting, such as dB(A) |
| Sound Level Meter |
An instrument for measuring various noise parameters |
| SPL |
Sound Pressure Level, the basic measure of noise level, expressed in decibels |
| Statistical Analysis |
A calculation performed by a Sound Level Meter on the noise levels measured during the measurement period to describe the statistical spread of the noise. |
| Type 2 |
General Field Grade for Sound Level Meter |
| Type 1 |
Laboratory & Field Grade for Sound Level Meters |
| Under Range |
The input to the Sound Level Meter is too low for the current measurement range. Change the range |
| Z Weighting |
Z weighting is a flat frequency response between 10Hz and 20kHz ±1.5dB excluding microphone response. |
Glossary of Terms 
