How do you know if UV LED light sanitizer really emits UVC rays?

There are a whole bunch of these handheld UVC germicidal wands being sold on Amazon, eBay, etc. Is there an inexpensive and simple way for consumers to test whether the light being emitted is really UVC and not UVA or UVB?

For example, if you had a Dosimeter test card that's used in industry, could you put it under the light wand and see whether it changes color? Or would the light output from the wands be too low for it to work?

But other than one of these test cards and an expensive UV light meter, is there something else the average consumer can do to tell if their light wand really does emit UVC light?