Dave Plowman (News) wrote:

The pictures in the service manual I'm using show a spring gauge, so I
presume that such things of suitable accuracy must be available.

Think what you need is called a spring balance. But it might help to know
what the actual application is.

It's to measure (and help set) the torque or pressure of various parts
of a tape recorder - the spool motors, pinch wheel, and so on.

The manual calls for one measuring up to 300g and one up to 3kg.

I think this looks as though it might be OK:

http://www.scalesexpress.com/product.php?productid=16552

even if its graduation is only 25g.

Daniele