Smart Meter Pro is the NEW 4th set of Smart Tools® collection. It includes 3 tools (Sound meter, Vibration meter and Lux meter). ① Sound meter Sound level meter uses your microphone to measure noise volume in decibels(db), and shows a reference. REMEMBER!! Most microphones were aligned to human voice (300-3400 Hz, 40-60 dB). Therefore maximum value is LIMITED by manufacturers, and very loud sound (90+ dB) cannot be recognized. You can trust the result in routine-noise levels (40-70 dB). ② Vibration meter (seismograph) Vibrometer uses the acceleration sensors to measure vibration or an earthquake, and it shows a reference as a seismic detector. The measured values are related to Modified Mercalli Intensity scale (MMI). If it is inaccurate, you can calibrate it so that maximum value is about 10-11. Please use it as an auxiliary tool. ③ Lux meter Light meter measures the ambient brightness with embedded light sensor. It is used to adjust the lighting required for plants or to check the brightness of a study room. Make sure that your screen with the sensor is facing the ambient light source (lamp, LED lighting, window, sun). * Pro version added Features: - No ads - Integration of 3 tools - Statistic menu (line chart) - CSV file exporting (max. 48 hours) For more information, watch YouTube video and visit the blog. Thank you. * It is a one-time payment. The app price is charged only once. ** Off-line support: You can open this app without any connection. After installation, open the app 1-2 times with your device connect to Wi-Fi or 3G/4G.