#1 Tip - Safety
Please make sure you understand the proper way of connection before heading to test a cable or a charger. Here is the right way to use:
When testing a cable:
PLEASE MAKE SURE YOU CONNECT BOTH END OF YOUR CABLE INTO QUALMETER FOR TESTING!!!
Cable test mode will be enabled when both ends of a cable have been connected with qualMeter. Then plug qualMeter into an 5V USB power source. The blue cable test indicator (the left one) will be turned on. You can find out the quality of this cable by reading the Quality Indicators on the left.
PLEASE DONOT CONNECT THE OTHER END OF YOUR USB CABLE TO AN USB POWER SOURCE!!! AS THIS MAY CAUSE DAMAGE ON QUALMETER!!!
Find out more in this post: http://forum.qoopow.com/t/caution-inappropriate-connection-may-cause-damage-on-qualmeter
#2 Tip - Simple reading and diagnostic
The testing result form qualMeter basic is very straight forward. There is pretty much no more details about it. What you see is what you get.
For example, If your setting is 2.4A with miniLoad and get Fair LED lights up. That means the output of your charger on 2.4A is in fair condition. As the common sense, Fair means it’s useable but not in the best performance. That’s it. 
You could play around with 2.1A. You should get Best LED lights up. Then that means your charger has no problem to give you 2.1A output. And to compare with the testing result you’ve got from 2.4A testing you can conclude that your charger is the best at 2.1A output.
#3 Tip - About the LED readings
The LED levels are grouped in 3 main groups Best, Fair and Worst. Each of two LEDs give you the idea that the top one is better than the lower one in this sub-group.
And we do have the 7th level which is the flashing red LED at the bottom. This is telling you that the cable is shorted or something is broken.
#4 Tip - It seems not testing my cable, why?
If you plug cable in for testing but only can get charger testing reading, that means your wire is broken or the connection is somehow losing.