touch weight

[Robert Scott]

Regarding the measurement of up-weight,
Newton Hunt wrote:

>>>
Up weight is measured by placing a likely weight on the key, pressing
the key down to let-off and using your fist hit the action lightly to
break the static friction of the action parts.  If the hammer raises
fast there is too little weight.  If it does not raise at all the
weight is too high.  The hammer should rise slowly but steadily.
<<<

This means that up-weight, and perhaps down-weight, are meant to
correlate to sliding friction, not static friction.  Is this
a generally accepted definition?  Or do some of you measure
up and down weight without tapping the action to break the
static friction?  I would like to know because I am considering
the design of a device to automatically measure touch weights
for each note, and it won't be right if I don't have the
the definition exactly right.

-Bob Scott
 Ann Arbor, Michigan