In article , "Grunff"
says...
Dave wrote:

:-) Thanks ;-)
Being resourceful (SWMBO says "tight") I was thinking more of a widget to
adapt a tyre pressure gauge ('seems like it should work) or some other
ingenious way of adapting something I might already have.

Yes, easy enoough to do. But you'll get the inside of your tyre gauge
wet. Depending on the type of gauge, this may not do it much good.

Why would you get water in the gauge? Just get a plastic 2litre Coke
bottle, attach a screw-in Schraeder valve from an old bicyle tyre to a
hole drilled near the top, attach the bottle to the tap with a bit of
rubber hose and a couple of hose clips. Pressurise the air in the
bottle by turning the tap on, check the pressure at the valve.