I’ve been reading up on tempered glass. I found a forum that talked about fixing thermopane windows with a broken seal and one of the contributors to the forum described what he thought might be a way to determine if glass was tempered by using a flash camera at night. It seems tempered glass reflects/refracts light differently.
Because we have LOTS of glass . . . full windows, panes, parts of panes (the broken ones are easy to tell, no testing necessary), having a reliable way to test a pane to see if it’s tempered is a must.
Tempered glass
This is the way tempered glass reflects/refracts the light. This is the sliding portion of the glass door in our living room. Tempered glass returns the flash from the camera as a mini sun, round with a glowing corona. This one’s a bit tricky as it has a screen behind it. Click the image to enlarge.
Not tempered glass
The non-tempered glass shows a different, more ragged flash reflection with a ragged corona.
I think the process would have produced clearer results if I’d cleaned the window . . .