Review on 🌬️ KT-401 Mini Air Ion Tester: Accurate LCD Display of High +/- Air Ion Concentrations by Gary Cole

I doubt this device has any idea what it's looking for or how close or far it might be. I wanted something more reliable for measuring negative ions than licking the back of my hand and holding it 1/4 inch from the ion emitters, this electronic device is not what I was looking for. The manual states that the device must be connected to a hard ground in order to work, but it is not configured for this and even if it were, there is no way to verify that the ground is properly grounded. From now on I will lick the back of my hand.