How to choose the right sound level meter
At present, there are many instruments for measuring sound, and the prices vary widely. The cheap ones are more than 100 yuan, and the expensive ones are more than 100,000 yuan. Regardless of the price, how to choose a suitable sound level meter?
(1) The sound level meter is in the catalog of measuring instruments under national compulsory supervision, and it needs a type approval certificate before it can be produced and sold (the same is true for imported instruments). So the most important thing is to have a CPA certificate (type approval certificate), otherwise there must be problems.
(2) If possible, try to send it to the Institute of Metrology to obtain a verification certificate. Note that it is a verification certificate, not a calibration certificate. Many people don't know their differences, and the calibration certificate only gives data, not conclusions, and it is up to customers to judge by themselves. The verification certificate must give conclusions and accuracy grades. A certificate will only be issued if all items pass the test. The items of the calibration certificate are not required, and the data of only one indicator can be given, or the data of all 10 items can be given. (Specific performance indicators can refer to JJG 188-2017)
(3) What is the type approval certificate? To put it simply, it is a certificate given after the full performance is qualified, and the full performance test needs to be done by a metrology institute above the provincial level to be effective. The full performance experiment is to ensure that the measurement data of the sound level meter is accurate and reliable under various extreme environments (such as temperature, humidity, electric field, magnetic field, electrostatic discharge, radiation, etc.). At present, no more than 10 domestic sound level meter manufacturers have obtained CPA certificates, and most of them are located in Zhejiang and Beijing.
(4) Accuracy and price issues: you get what you pay for, level 1 has high precision and high price; level 2 is cheaper. Non-standard (without CPA certificate) sound level meter is less than 500 yuan. If the requirements for measurement accuracy and accuracy are particularly high, it is recommended to use BK, and of course the price will not be lower than 100,000. Conventional domestic sound level meters are also sufficient, and the best one is Aihua.
(5) Do not expect the accuracy of the sound level meter below 500 yuan, it is still possible to play with it as a toy.
