Review on 🔊 Extech 407730 Digital Sound Meter: Measures Sound Levels from 40 to 130DB with Accuracy by Andrew Krishna

Expensive but works well. The only problem is that if you're recording for a long period of time (e.g. several days), the system won't switch off when the batteries are low, meaning they can become completely discharged and leak. I caught it in time, the leak is small but not big. I hope it doesn't die later from the slow corrosion inside. This can be avoided by purchasing non-leakage AA lithium batteries. They are much more expensive than alkaline ones, but not nearly as expensive as these devices!