help a beginner measure mc in wood with confidence

[Gene Nelson]

>
> Another is to build a direct reading MC gage with a strip of
> spruce and a cheap dial indicator. Even if you don't bother to
> try to calibrate it to any specific MC, it can still be used
> as an indicator of dimensional change with Terry's approach
> without having to haul the panel out to measure it.

Nice gauge - thanks for the pic.

>>     < Do you have the sling hygrometer? What brand and where did you get 
>> ?
>
> Got one, but it's hard to swing in a 6" wide box. <G>

Maybe this is why it is sometimes called a psychrometer?

>>     I suppose that after the board is ribbed, this same movement can be
>>     measured as available crown with similar associations with changing
>>     environment?
>
> MC changes can be observed this way, but not measured, and not
> after the piano is strung. Crown in a strung piano doesn't
> usually vary much at all with MC changes.

On a rib crowned board in a shop that the environment is difficult to 
control, changing available crown (prior to stringing) has brought me to 
this.
Adjustable plate bolts and vertical hitches are a must.
Thanks Ron.
Gene