Welsh Densichron densitometer

Hi.

I have a 1970's vintage Welsh Densichron transmission densitometer. It seems
to work fine with one exception. The readings are not aligned at the higher
densities. Since the slope of the response is a straight line I could just
multiply by the slope factor. Sort of a pain though, so I would love to
return the displayed density readings to accuracy.

Any old timers know how to adjust this?

Rick


For example.

Actual density (verified elsewhere).
..08
..25
..41
..
..
..
2.66
2.81
2.97
3.11

As this densitometer displays.
..08
..25
..40
..
..
..
3.10
3.22
3.40
3.55

"Rick Mintz" wrote in message
...
Hi.

I have a 1970's vintage Welsh Densichron transmission densitometer. It
seems
to work fine with one exception. The readings are not aligned at the
higher
densities. Since the slope of the response is a straight line I could just
multiply by the slope factor. Sort of a pain though, so I would love to
return the displayed density readings to accuracy.

Any old timers know how to adjust this?

Rick
snip

I am not familiar with this equipment, so my comments may have no value
whatsoever...
My densitometer has a zero adjust, and a calibration adjust. Each adjustment
affects one end of the density "slope". You adjust the zero, and the
densities at that end (white/clear) are now correct. Then you adjust the
calibration, and that brings in the densities at the other end
(black/dense). If the calibration adjust is off, the higher densities will
be off.
Before turning the screws on your machine, please go back and read my first
sentence!

Ken