When you're ready to take noise measurements, it's strongly recommended that you perform a field calibration using an Acoustic Calibrator. You should calibrate your sound meter before you start to measure, and then once you've finished you should perform a reference check against the calibrator and make note of any drift that has occured. You can find out more about performing Field Calibrators by reading this post and watching a short video.
LAB23, the latest guidances from the United Kingdom Accrediation Service (UKAS), states the recommended calibration intervals for different types of measuring equipment, including:
For a professional calibration and repair service with a fast turnaround, contact Castle Calibration or visit www.castlecalibration.com and search for your equipment.
The Castle GA601 produces a calibration tone of 1000Hz at a level of 94dB re 20µPa at the microphone. The GA601 Acoustic Calibrator comes with a 12 Month Manufacturers Calibration with Certificate, however if you require UKAS Calibration this can be added below.
GA607 Acoustic CalibratorThe GA607 meets the demanding standards of a Class 1 calibrator. It features two calibration levels, 94dB and 104dB re 20µPa both at 1kHz and is supplied with required barometer. The GA607 Acoustic Calibrator comes with a 12 Month Manufacturers Calibration with Certificate, however if you require UKAS Calibration this can be added below.