how often should a sound level meter be calibrated

An Optimus Sound Level Meter being returned for recalibration. It’s well known that Sound Meters inevitably need to be calibrated to keep performing accurately, but a question we’re often asked is, “How often does my Sound Meter need to be Calibrated by a calibration lab?“. Sound level meter calibration by the manufacturer is something I recommended annually. The Acoustic Calibrator fits over the microphone and outputs a consistent sound level for the microphone to detect. This means that the meter level should show a level equal, or very close to the output level. The first, field calibration, is what you would carry out before (as possibly after) each measurement using a reference acoustic source such as an acoustic calibrator. Sound Meters – How often should my Sound Meter be Calibrated? (e in b)&&0=b[e].o&&a.height>=b[e].m)&&(b[e]={rw:a.width,rh:a.height,ow:a.naturalWidth,oh:a.naturalHeight})}return b}var C="";u("pagespeed.CriticalImages.getBeaconData",function(){return C});u("pagespeed.CriticalImages.Run",function(b,c,a,d,e,f){var r=new y(b,c,a,e,f);x=r;d&&w(function(){window.setTimeout(function(){A(r)},0)})});})();pagespeed.CriticalImages.Run('/mod_pagespeed_beacon','https://www.norsonic.asia/to-calibrate-or-not-and-how-often/','82dtZm2p5Q',true,false,'IkF-BMoVhHw'); To calibrate a sound level meter we use what is called a sound calibrator — such as the Norsonic sound calibrator Nor1251, Nor1252 or Nor1253 and the new series Nor1255, Nor1256, Nor1257 and Nor1258. Do you calibrate a sound level meter frequently? – Reference to the maximum period recommended in the table at the back of the LAB23 document depending on the type of equipment used. The actual calibration is then carried out by mounting the calibrator onto the microphone as shown in the picture and then switch the calibrator on. The whole instrument is then passed into the calibration area where it is subject to a battery of tests (essentially the same tests that we do when we made the instrument) to check that it still meets all of the performance points that it did when it was new. If the instrument has had to offset any variation, it should display this as well. If you want more information on pricing, contact Cirrus today as they can calibrate any instrument from any manufacturer. We also often get asked why an instrument needs to be calibrated every time it is used when you have a certificate of calibration. If there’s any variation between what the calibrator is outputting and the what the microphone is receiving, the sound level meter can offset the difference to ensure your measurements are consistent and accurate against a consistent noise source. This involves sending your sound level meter and Acoustic Calibrator back to the original manufacturer for them to calibrate and verify the instruments. Building acoustics multi channel analyzer ISO16283 ASTM E336. An Optimus Sound Level Meter being returned for recalibration. (function(){for(var g="function"==typeof Object.defineProperties?Object.defineProperty:function(b,c,a){if(a.get||a.set)throw new TypeError("ES3 does not support getters and setters. Calibrating using a Sound Calibrator The limitations of a field calibration are that it is only checking the performance of your instrument at a single point, whereas when you are undertaking a real noise measurement, your instrument will be recording a wide range of frequencies and levels which are combined to provide the noise parameters that you need. “The instrumentation system, including the microphones, cables, and windscreen if used, shall meet the requirements of IEC 61672-1:2002, class 1, and the filters, if relevant, shall meet the requirements of IEC 61260:1995, class 1.”, “Select systems for measuring sound pressure levels, including microphone(s), cable(s), windscreen(s), recording devices and other accessories which conform to BS EN 61672-1, Class 1, for free-field application, as appropriate. Before we go into how often you should be calibrating, I just want to quickly recap what we mean by sound level meter calibration. Why calibrate? What do we mean by this? To give an example of what happens at Cirrus, when an Optimus sound level meter comes into our calibration lab, the microphone capsule is removed and checked using our reference electrostatic calibration system. If the sound level meter fails to indicate the correct sound pressure level, its sensitivity is adjusted until it indicates the correct value (some countries put restrictions on your right to adjust the meter, if your measurements shall comply with certain standards). However, the more often you have the sound level meter calibrated, the less risk of your measurements being questioned. This post contains information about the best and easiest methods of performing a field (pre-measurement) calibration for your sound meter and other noise monitoring equipment. Noise 101: What is Equivalent Continuous Sound Level (Leq)? Before we go into how often you should be calibrating, I just want to quickly recap what we mean by sound level meter calibration. Always check what you are getting when you are paying for the calibration of your equipment and ensure that it meets the requirements of any standards or regulations that you are working to. It involves using an Acoustic Calibrator that is usually supplied as part of your measurement kit. If not, the accuracy of your measurements could be called into question. Unfortunately, the word calibration has ended up having two meanings; to describe the use of a sound calibrator in connection with a measurement and to describe periodic verification which is carried out in a Calibration Laboratory. How Often Should The Sound Level Meter Be Calibrated (field Calibration By "acoustic Calibrator" Or Pistonphone)? I always recommend erring on the side of caution, especially when you are measuring to Standards, Regulations and Guidelines. Hence, even these have been divided into several types (called classes) depending on their level accuracy and ability to maintain a stable level. An Acoustic Calibrator being used on an Optimus Sound Level Meter. Sound Level Meter Calibration and doseBadge Noise Dosimeter Calibration. However, the cost of not recalibrating could be far higher if your business is fined or prosecuted for breaching the Regulations. One may therefore say that a calibrator is just as much a device for verification of appropriate operation as it is a device for re-adjustment of the sensitivity of the sound level meter. If it’s field calibration, before and after each measurement. Question: C. How Often Should The Sound Level Meter Be Calibrated (field Calibration By "acoustic Calibrator" Or Pistonphone)? Recalibration essentially checks all of these components and that the performance of the equipment is the same as when it was manufactured. On a regular basis (e.g. D. Should Your Precision Microphone (such As Your Sound Level Meter -not Your Microphone For Voice Recording) Be At 0-deg Incident Or 90-deg Incident With The Noise Source? As with any precision instrument, components age and can be subjected to changing environments. Do you calibrate a sound level meter frequently? If you’re measuring to any Standard, Regulations or Guidelines it is vital to calibrate your sound level meter. That means you can compare the reading you have just taken with a similar reading you may have taken 6 months ago safe in the knowledge that any variation in performance has already been taken into account. A sound level meter (or any noise measurement instrument) should be calibrated otherwise it can be very difficult to show traceability when the measurements are challenged now or in the future. However, the cost of not recalibrating could be far higher if your business is fined or prosecuted for breaching the Regulations. For field calibration, you should be using your Acoustic Calibrator before and after each measurement. Periodic Verification The Acoustic Calibrator fits over the microphone and outputs a consistent sound level for the microphone to detect.