AT34 USB 3.0 Tester,USB Power Meter 30V 4A USB Voltage Tester Multimeter Digital Multimeter Current Tester Voltmeter Ammeter IPS Color Display Capacity Power USB Charger Tester

I am working on very low power IoT devices and I wanted an easy way to get a ball park measurement for how much power was being used without hooking up an oscilloscope or other equipment. I compared the measured power consumption against the o-scope and got 9.39ma versus the 9ma shown by this unit. It is close enough for me to use it as way to judge whether code changes improve the deep sleep current drain.This is a great tool if you want to quickly check current draw by a USB device.

It definitely needs a heat sink and larger enclosure. Values are approximate as they aren't static.Charging a phone > 3.6 watts, 5.14v, 122mwh. LED light >1.9 watts, 5.19v 158mwh. No problems.The LED has a heat sink and runs hot to the touch. The tester shuts after about 5 seconds.

Glad i bought this. I found 2 adapter that was an out rite lie rated at 2 amp only doing 1 amp or less straight to the garbage they went.In short if you have an adapter that is taking a long time to charge something test it with this to see the output when the battery is dead many companies will over rate an item 2 amp you can expect 1.7 amp or better and watch the voltage sag if it less than 4.5 volts at full load toss it in the garbage. i had one rated at 2 amp and it was 3.97 volts @ 1.1 amp total garbage. The other barely 1 amp @ 4.9 volts garbage it went. Folks with todays tech stuff you need at least 2 amp and a stable voltage to get the phones and tablets charged in a timely manner and have enough reserve power to still use the devise.The battery in the devises is 4.2 volts and charging 5 volts in gets regulated at 4.2 if there is a bad voltage sag it takes even longer to charge. Im getting one 2.4 amp amazon basics adapter to see how it works to replace the 2 that i tossed out. If it does what its suppose to i may buy another one if not ill send it back but ill post a review on it as well.

I would have loved to have given this 5 stars because it's really accurate and it provides all the information you would need on a USB port. The Display while Bright and clear has an issue with some of the values being so small that only younger people will be able to read them clearly. I had to really get up close to see some of the Values. Luckily the Most important stuff is easy to read.

I like that I can test current for devices that don't need a lot of power. With 5 digits displayed, it covers most of my needs for usb-powered things.

The media could not be loaded. Nice display that is very easy to read. It works well, does what I wanted and I'm happy.Testing USB devices, USB power supplies, Powerbanks, and USB ports was easy and accurate.

I have not had a lot of time to test and use this. I have used it a few times and it was dead on perfect in its reading. I have to figure that it will stay this way. It comes with the device in a nice small storage case. This case is a nice touch as it will keep dust and other foreign objects from getting in and on it.Operation is simple. (Once you find the buttons.) It is very bright and can be seen anywhere you use it. So far so good. If I experience any troubles i will update this review to reflect them. But I do not think that is going to happen.

While I don't have any way to verify that this product provides accurate readings, it does give reasonable numbers when slow vs. fast charging a phone and using vs. idling an external HDD. I assume its readings are accurate, and they seem pretty stable.The user interface leaves much to be desired. It has just a single (bottom mounted!) button, which you're supposed to push and hold until the on-screen "cursor" cycles to the option you want. Adding at least 2 more buttons (to have up, down, and select) would be optimal, but, even without adding more physical buttons, the device could be improved by making commonly used options first in the list. I realize that "commonly used" varies by user, but I'd venture to guess that turning the display off and changing temperature units are options that people need less frequently than resetting the stats and rotating the screen, yet rotating the screen is the very last option.