Murmansk69 wrote:
Thanks for replies, it needs to have a chime unit that is separated
wirelessly from the infrared detector so that the person in the back
room can hear it and so it's not heard in the shop. It also needs to be
"off the shelf" not something involving adaptation of something else.

I've done a bit of Google searching and come up with a few ideas

Prompted by replies to a question here about PIR sensor alerts, I
recently bought a 'Jaguar' (IQ Europe Ltd.) 'battery powered PIR sensor
with portable chime alert and light adaptor'. (In B&Q, 50 quids.)

They have the same without the light adaptor for about =A310 cheaper.

Seems to do what you require. But I guess you would place it somewhere
inside the shop? Unless pedestrian and other traffic on your street is
bound only for you.

I haven't tried volume control; I assume none. But you could place it
under (a) cushion(s). Or, maybe the light would do as a silent alert.

Incidentally, initial impressions on my unit: (i) I wonder how long the
AA batteries will last (three in sensor, three in chime); (ii) I wonder
will the PIR sensor go the way floodlight sensors go when exposed to
weather, i.e. fail after two/three years? (iii) cats; I'm now
attempting to use some sort of netting to discourage them from their
'traditional route' into my garden; (iv) a lot easier to fit and set up
-- ten minutes at most -- compared to something that I'd kludge myself.

Best regards,

Jon C.