Review on Digital Quality Detector Tester Monitor by Jason Dahlkemper

First off, this is a great little PM detector. The interface and readings are simple, responsive, and accurate. BUT, I have to be finicky about a few things. So let's get started. 1) When the reading drops to zero (e.g. indoors) all the numbers turn red for some reason and say the text below is "Heavily Dirty". So these are definitely two software bugs. The numbers should stay GREEN and not turn red. And they are contaminated with typos. I understand it is made in China. But come on. At $50 apiece they could at least fix it by now. 2) There is no battery, it is powered by USB 2.0 interface. That means to do mobile measurements you have to plug it into a phone charger and carry two devices with you, like nunchucks for nerds or something. I think that's a serious design flaw because the whole point of such a small device is its portability. I feel like they should have used 2 AA batteries instead of (or in addition to) the USB interface. 3) There must be a way to toggle between Fahrenheit and Celsius. I agree the metric system is better. But I think the United States is one of the biggest markets for these things, and we're more familiar with Fahrenheit.