"Dave Plowman (News)" wrote in message
...
In article ,
dennis@home wrote:
I bought a box of indigestion tablets the other day. Meant to be 24
tablets - three packs of 8. Cardboard box not sealed. On opening it at
home discovered a pack missing. So presumably stolen out of the packet?
But how come the self service checkout didn't say the weight was wrong?
It
seems to do so for everything else...


The machine weighs stuff so you can't put it on without scanning, very
few of them actually check the product weight against what is expected.

That goes against what I'd expect.

It must check against a database of product weights, rather than just noting
every time the weight increases, otherwise you could scan one item and put
several items on the bagging scale as a single movement.

As a test, I tried just that when the system was first introduced - not to
defraud, but simply to see how it coped. I scanned one can of soup and
placed one can on top of the other and put that 2-can unit on the scale. It
told me "wrong product weight" or "unexpected item in bagging area". It even
warned me when one of the loose apples fell out of the bag and remained on
the scanning area when I put the bag on the scale - so it warns for too
little as well as too much weight.