By Winged Wolf
Basic Methods
The most obvious way to check a shield is to scan its surface and look for any areas where there are holes, or spots which are weaker, or uneven. Holes obviously could allow someone or something to go right through…weak areas are target points, and flaws in the shield may be less resistant to some attacks than other areas. You can also do a “tap test”…weak blows to the shield to see if any areas react differently from other areas.
More Advanced Methods
The next thing to do to check a shield is to check the frequency spread…if you can penetrate it with one frequency, you could use it to build on the other side and do what you like. So, aim energy in turn in as many different frequencies as you can, all along the spectrum, looking for a point where a frequency passes through…or even deeper than the others.
Next, the shield should be checked for susceptibility to crushing, and to sharp fine-point blows (needle puncturing). If it stands up to all of these techniques without cracking, then you can be pretty sure you have a very good shield.