Vintage Decibel Meter vs Smartphone App

[bigb]

I was given this Sound meter by a retired aviation mechanic. One of the batteries is special so as soon as I locate one I'll be in business. I am wondering about the accuracy of it compared to some of the smartphone apps for decibels. I want to use it to measure sound levels of portable generators.

[ronsii]

I was given this Sound meter by a retired aviation mechanic. One of the batteries is special so as soon as I locate one I'll be in business. I am wondering about the accuracy of it compared to some of the smartphone apps for decibels. I want to use it to measure sound levels of portable generators.

Smartphone apps will vary depending on how specific their programming is to your actual phone for frequency sensitivity... but I would think a decent phone would be accurate within a db...

If it's a 22 or 45 volt batt you could just stack some 9volts together

[bigb]

It's actually a 30 volt, about $30 on Amazon