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Chapter 5

Calibration

5.1 Introduction

Calibration is an adjustment of your analyzer to measure and display correct values. The

sensitivity of the transducer as well as the response of the electronic circuitry can vary slightly

over time, or could be affected by environmental conditions such as temperature and humidity.

While you are unlikely to ever experience a large drift or change in sensitivity with the

analyzer, it is nevertheless good practice to perform regular calibrations, normally before and

after each set of measurements. Often calibration is required by measurement standards, such

as IEC 61672–1.

If you want your analyzer to remind you when the next Accredited/Traceable calibration is due,

you can set it up on the Reminder tab of the Calibration screen. See section 5.9.

You can check the complete measurement chain during long-term measurement using Charge

Injection Calibration. See section 5.10.

5.2 Acoustic Calibration

Acoustic calibration is the preferred calibration method when measuring with microphones,

particularly when standards and regulations require calibration before a measurement. The

method involves applying an acoustic signal of known magnitude and frequency to the

microphone, which calibrates all the analyzer’s components (microphone, preamplifier and

electrical circuitry).

5.3 Sound Level Calibration

To perform acoustic calibration use Sound Calibrator Type 4231. It provides a stable sound

pressure at 1 kHz and has minimal susceptibility to environmental factors. The procedure itself

is relatively simple, and on the analyzer the procedure is referred to as the Standard

Calibration procedure.

The procedure for performing an acoustic calibration and instructions on how to fit the calibrator

are given in the following section.

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B&K 2250 Light Manual de usuario Pagina 63