Even if sound level meters are easy to understand and use, it is beneficial to understand few basic terms related to it. It helps in choosing the required sound level meter with ease.
Why is it important to use a Sound Meter?
The goal is to ensure that all sound exposures are safe for human ears Therefore a sound level meter is used to measure the volume of sound waves. You can also find this meter as a decibel meter.
Application of Sound Meter
- Industrial plants
- Road and rail traffic
- Construction work
- IEC 61672 - The worldwide standard for noise level meters is known as IEC 61672, and it was developed in Europe. The checking of tests and performance for sound meters, as well as information regarding the testing equipment used to ensure that sound meters live up to their manufacturers' claims, are both covered by this standard. The standard also addresses the content and organization of verification tests.
- Decibel (dB) – The decibel, abbreviated as dB, is a unit that is used to measure the strength of sound. On a logarithmic scale, one unit of measurement known as a decibel is equal to the ratio of one energy to another. Despite the fact that DB and bel really aren't exact mathematical units, a decibel is equal to one-tenth of a bel. They can't be measured since all they are is a ratio between two different values.
- Class 1 – A precise sound meter designed for use in a laboratory or on the job is what the international standard IEC 61672 refers to as "Class 1." These meters are sometimes referred to as "Type 1 sound meters."
- Class 2 – This pertains to the overall grade meters, as stated in the IEC 61672 specification. Until recently, we used the term "Type 2" to refer to these meters.
- Dose - Dose limits are typically established by government entities to restrict a person's amount of noise.
- Dose Percentage – Using a specified level for 8 hours, the noise exposure's dosage percentage is derived.
- Time Weightings: Fast, Slow, and Impulse - Each of these three modes is referred to as an "impulse." In order to accurately measure noise levels, the sound level meter uses time weightings. Devices may be configured in such a way that a slow setting responds slowly to changes in noise, while a rapid setting responds quickly. Devices that are activated by the sound of a stimulus react rapidly, but take longer when the sound intensity decreases.
- Frequency – Hertz (Hz), kilohertz (kHz), and megahertz (MHz) are the units of measurement for frequency, which refers to the number of full vibration cycles that occur in one second.
- Frequency Weighting – To generate the appropriate measurement, "weighting" refers to the process of altering the responsiveness of a sound level meter in the frequency. The concept of frequency weighting refers to the relationship that exists between the signal level that is shown on the screen and the major component of relatively steady sinusoidal input signal. This relationship is established as a function of frequency.
- Equivalent Continuous Sound Level (Leq) – The Leq is a way to measure the total amount of noise you are exposed to over a certain amount of time.
- LE (SEL) – It is a Leq lowered to the speed of a single second for the sake of clarity. Noise events with various durations are analyzed using this statistic. Exposure duration multiplied by the logarithm of sound exposure yields Leq.
- Ln – The 'n' indicates the percentage of the total that was surpassed. In statistical noise analysis, the Ln value is utilized. In other words, if you get an L90, the noise level was over a certain threshold for 90% of the time the measurement was completed.
- Peak Sound Pressure (Speak)– When we talk about "peak level," we mean the pressure wave's true apex as opposed to the measurement's greatest sound level.
- Variable range– On a sound level meter, the Variable range is the area where you can measure the difference between low and high sound levels that cause the meter to overload.
- Octave Band Filters – One way an Octave Band Filter might help decipher a complex sound is by breaking it up into discrete bands of different frequencies. The octave filters of a sound level meter may be either 1:1 or 1:3.
- Weighting: ‘A’– The noise sensitivity of the human ear is represented by a standard weighting of audible frequency ranges. This frequency weighting may be measured using either dB (A) or dBA as the unit of measurement.
- Weighting: 'C' – When calculating the "C" weighted average, low-frequency sounds are assigned greater weight than they are when calculating the "A" weighted average. dB(C) or dBC are the units of measurement that are used for this frequency grading.
- Weighting: 'Z' - Z-weighting creates a spectrum that is as flat as possible from 10 Hz to 20 kHz, with a difference of just 1.5 dB. This frequency grading may be measured using either dB(Z) or dBZ as the unit of measurement.
Types of Sound Meters
Sound Meter Class 1
Used for precision-grade assessments. The main use is in the laboratory.
Sound Meter Class2
Class 2 is used for noise level assessments in industrial, commercial,educational, or residential scenarios.