measuring silver content with XRF gun

I have heard about the use of this gun to identify the quantity and purity of silver in an item but i have never met anyone who used one.
can someone shed light on this device use . I have a sterling candle sticks with weights , can this gun be used to exactly tell how much silver by percentage is in the candle and the purity of the silver?

 

It only reads the surface. It cannot determine what's underneath or percentage of the whole.

 

I have quite often had stuff tested at my bullion dealer's shop (the deal was one pound in the charity tin for each test) and I can say that the X-Ray penetration is deep enough not to be confused by many plated items, and rolled gold may show the high base metal content.
It really is most reliable on solid metal objects, though, filing of suspected plated items is advised, it may be only on very worn plate that the subsurface metal is vulnerable.

Best to assume it is only really a surface test and proceed accordingly. I may have been lucky as I have read of people chargeing quite a high fee for the use of the instrument, possibly understandable as they are still very expensive.

It would be great if like many other electronic items they came down in price enough to be widely avaliable but unlike computers and televisions they are not really something everyone wants. Last time I looked the Niton XRF was about $20,000, but I have not looked for somw years.

Unhappily nothing but experience will give an answer to the silver weight of loaded items, this usually comes from scrapping them and remembering all the results.