Chris,
I always knew you were a genius!
I had been wracking my brain, Brett, on how to dither your instrument by me=
ans of something doing work out on your pier. Clearly the recommendation p=
rovided by Chris is the way to start checking whether dithering can be bene=
ficial.
You and/or Dave mentioned in earlier messages some work in which you i=
mproved stability against creep by annealing the spring at elevated temper=
ature, while under load (if I recall and understand properly what was said)=
.. Certainly there is a significant benefit derived from this, due to the t=
emperature dependence of diffusion processes involving dislocations. You c=
an pin them (basis for work hardening) more rapidly by this means. You can=
also accelerate the process by taking a hammer to the pier. Don't take my=
word for it; look in some of Erhard's 'practical guides' on his outstandin=
g online material, such as at
http://www.geophys.uni-stuttgart.de/oldwww/seismometry/man_html/index.html
I believe I remember him saying there that one could beat on the pier =
with a hammer to reduce the time required to get operational.
It does my heart good to know that my 'primitive instinct' toward behaving =
like a 'sledgehammer mechanic' can actually under some conditions be benefi=
cial!
Years ago I did a study using the very soft metal indium, clamped in a=
n extensometer that I developed around the SDC sensor. I discovered that t=
he wire could do all kinds of crazy things, depending on history of treatme=
nt. Moreover, it never was found to be in a state that could be thought of=
as a truly 'fixed length'. By tapping on the table holding the extensomet=
er , I could 'hammer down' to a semi-final (one might think, equilibrium) s=
tate much faster than by waiting for it to creep there, under load change, =
without the tapping. I actually gave an invited lecture at the Universit=
y of Texas in Austin based on this work, titled "Peculiar collective world =
of mesoanelastic complexity" (1994, the Center for Nonlinear Dynamics, run =
by Harold Swinney).
Randall
Chris,
I always knew you were a=
genius!
I had been wracking my b=
rain, Brett, on how to dither your instrument by means of something doing w=
ork out on your pier. Clearly the recommendation provided by Chris is=
the way to start checking whether dithering can be beneficial.
You and/or Dave mentioned =
in earlier messages some work in which you improved stability against=
creep by annealing the spring at elevated temperature, while under load (i=
f I recall and understand properly what was said). Certainly there is=
a significant benefit derived from this, due to the temperature dependence=
of diffusion processes involving dislocations. You can pin them (bas=
is for work hardening) more rapidly by this means. You can also accel=
erate the process by taking a hammer to the pier. Don’t take my=
word for it; look in some of Erhard’s ‘practical guides’=
on his outstanding online material, such as at
http://www.geophys.uni-stuttgart.de/oldwww/seismometry/=
man_html/index.html
&nbs=
p; I believe I remember him saying there that one could beat on the p=
ier with a hammer to reduce the time required to get operational.
It does my heart good to know that my R=
16;primitive instinct’ toward behaving like a ‘sledgehammer mec=
hanic’ can actually under some conditions be beneficial!
Years ago I did a study usi=
ng the very soft metal indium, clamped in an extensometer that I developed =
around the SDC sensor. I discovered that the wire could do all kinds =
of crazy things, depending on history of treatment. Moreover, it neve=
r was found to be in a state that could be thought of as a truly ‘fix=
ed length’. By tapping on the table holding the extensometer , =
I could ‘hammer down’ to a semi-final (one might think, equilib=
rium) state much faster than by waiting for it to creep there, under load c=
hange, without the tapping. I actually gave an invited le=
cture at the University of Texas in Austin based on this work, titled ̶=
0;Peculiar collective world of mesoanelastic complexity” (1994, the C=
enter for Nonlinear Dynamics, run by Harold Swinney).
Randall
=