My prior post inquired as to a cheap ink and paper that could be used to
test out my recently acquired barograph from an estate sale.

After some trial and error and with the group's help, I have managed to
get some accurate traces:

https://imgur.com/a/kKWKhQh

However, at least one issue still remains: the large ink spot you see
occurs within an hour of me refilling the tiny ink well on the device
arm. Once all that ink "hemorrhages", the trace then proceeds as you see
with no more spots. Any idea what could be causing this? Am I adding
too much ink each time?

One other thing I'd like to ask about is paper. For the chart, I had
printed them out on a piece of Georgia Pacific standard 20 lb weight
8.5x11 multipurpose paper and backed it with a couple of strips of
packing tape in the event a bleed-through occurred (and good thing I
did!). Suggestions for maybe a thicker paper I could try would be
welcome, with the idea to increase absorbency and still keep cost low.
In a pinch, I've been thinking of just doubling up the sheets I have
except the new thickness would not be uniform and glue would decrease
absorbency.

Thanks in advance.

JJ

On Wed, 5 Feb 2020 11:32:23 -0500, J-J wrote:

https://imgur.com/a/kKWKhQh

However, at least one issue still remains: the large ink spot you see
occurs within an hour of me refilling the tiny ink well on the device
arm. Once all that ink "hemorrhages", the trace then proceeds as you see
with no more spots. Any idea what could be causing this? Am I adding
too much ink each time?

Was the drum moving when the blob appeared, or was it stopped? If the
clock mechanism had stopped, I could see why there was a blob.
However, if it was moving, as in the visible trace in the photo, I
would ask what is different between when the blob formed and when it
did not? Other than a stalled or erratic clock mechanism, it could be
a "bubble" in the paper, where it was warped or curled, some defect in
the paper itself, or one of the problems mentioned in the article at:
https://www.metcheck.co.uk/blogs/barographs/156686919-how-to-get-a-good-barogram
"The two halves of the nib bucket should be of even length..."
If only one point is touching the paper, I think you might get a blob.

One other thing I'd like to ask about is paper. For the chart, I had
printed them out on a piece of Georgia Pacific standard 20 lb weight
8.5x11 multipurpose paper and backed it with a couple of strips of
packing tape in the event a bleed-through occurred (and good thing I
did!). Suggestions for maybe a thicker paper I could try would be
welcome, with the idea to increase absorbency and still keep cost low.
In a pinch, I've been thinking of just doubling up the sheets I have
except the new thickness would not be uniform and glue would decrease
absorbency.

Dunno. I was wrong about the paper needing to be absorbent (see above
Metcheck URL). I suggest you try a variety of paper types and see
which works best. Coated, not coated, 22 lb, vellum, photo paper
(glossy or matt), butcher paper, wax paper, premium clay coated
plotter paper, etc.
https://plotterpaper.plotter-paper-rolls.com/2014/07/17/premium-coated-plotter-paper/
Visit an art store and see what they have to offer.
Also look for "pen plotter paper":
https://www.graytex.com/pen-plotter-paper.htm
The pen is critical because most "plotter paper" is for inkjet
plotters.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558