TM834 professional digital noise meter 1. 30 ~ 130dB, A/C switching, 2. dynamic display ... frequency Product Name: TM834 professional digital noise meterProduct packaging:TM834 professional digital noise meter TM834 digital noise meter, 30 ~ 130dB, A/C ... time measurement function online, mainly is suitable for the environmental noise site, building, building, vehicle inspection, hospitals, detection.