How to determine whether a sound level meter's measurement is correct
The sound level meter is the basic instrument for measuring noise, and now the sound level meter has been widely used in our social life. It can be used in environmental protection, labor hygiene, industrial enterprises, scientific research and teaching and other fields to complete environmental noise measurement, sound power level measurement, equipment noise measurement and architectural acoustics measurement, etc.
During the use of the sound level meter, it must be sent to the Metrology Institute for verification of the sound level meter every year. After passing the verification, a verification certificate will be issued, and it can be used normally only after a qualified conclusion is drawn.
The calibration certificate of the sound level meter is useless, and it can only be used normally if a verification certificate is issued and a qualified conclusion and accuracy level are drawn. The daily verification of sound level meters requires a lot of equipment, such as calibrator, standard condenser microphone, signal generator, measurement amplifier, tone burst signal generator, precision attenuator, voltmeter, sound source, anechoic box (free field), etc. All equipment needs at least 30W or more, and it takes up a lot of space, so there are certain technical requirements; at the same time, there are not many instruments for sound level meter verification, and the standard devices have to be submitted for inspection every year, so it is not cost-effective to establish a complete set of acoustic verification devices. Many provincial metrology institutes have not established sound level meter verification devices, and cannot issue sound level meter verification certificates.
There are some precautions when using the sound level meter. When using the sound level meter, pay attention not to connect the two poles of the battery reversely. When the sound level meter is not used for a long time, the battery should be removed to avoid battery leakage and corrosion of the sound level meter. Pay attention to replace the battery in time when the voltage of the sound level meter is insufficient.
The sound level meter is powered by a battery. You should check whether the battery voltage meets the requirements. The meter switch is placed on the "battery level", and the "attenuator" can be set arbitrarily. At this time, the indication on the meter should be within the rated battery voltage range. Replace the battery. Pay attention to the polarity when installing the battery or external power supply, and pay attention to the polarity when installing the battery or external power supply.
