high accuracy sound level meter as-156b auto range selection for testing sound noise with decibel monitoring indicator tester

auto range selection and digital display with no guessing errors.
* can memorize 30 groups of measurement results and measuring conditions. offers 4 measurement parameters: lp (sound level); leq (equivalent continuous a sound level ); lmax ( maximum sound level) and ln (percent of all readings over alarm value set ). permits choice "a", "c" , "f" weighting and "fast" / "slow" response times..syi