There are two primary applicable standards that apply to sound level meters.
The JISC1502 (IEC651, Type 2) Standard applies to general-purpose sound level meters, which is typically used to measure environmental noise in commercial, industrial and residential applications.
The JIS1505 (IEC651, Type 1) Standard is reserved for precision grade sound level meters. The Type 1 instrument is used whenever high accuracy and repeatability is required such as sound studies in various fields including laboratory and other critical sound pressure level measurement applications.
Pro-measure.com has been providing Sound Pressure Level Measurement instruments for industrial, commercial, residential and laboratory applications for over Twenty Years. We will be happy to assist with any of your sound level measurement questions in order to ensure that your select the correct instrument for your application.