The context for this would be interesting, I would think hammering would decrease conductivity (guessing) but in any case I don't have any references that mention more than a minute change.
EDIT - So it was a rubber mallet, I am more confused.
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Or c) Helping restore contact in joints or welds where a bit of oxide may have formed?
I would like to thank you very much. I'm cleaning my keyboard of coffee...
Which brings me to my next point.
Those bass shakers are capable of vibrating a 7.5 ton granite table at 95 hz at the 90 micron level...which coincientally, is the exact optimum frequency and amplitude for electron "run in" and fermi sub-orbital re-formation of the grain boundary quasi static potential...
My charge for this service is minimal. 200 dollars per ounce..
jn
And a minute late.
An externally hosted image should be here but it was not working when we last tested it.
se
And a minute late.
An externally hosted image should be here but it was not working when we last tested it.
se
Akela had missed, I know. ((C) Rudyard Kipling)
This works very well at home (wife)
No, no jn. Then, silence will drive you crazy
DF96 and associates accept no claims for consequential damage allegedly caused by the reading of our posts in front of keyboards while consuming hot beverages.
WARNING: This coffee contains coffee. It was prepared in a kitchen where hot water and electricity may be used. May contain nuts, lactose, gluten, caffeine. Do not consume in the vicinity of electrical equipment or humour.
WARNING: This coffee contains coffee. It was prepared in a kitchen where hot water and electricity may be used. May contain nuts, lactose, gluten, caffeine. Do not consume in the vicinity of electrical equipment or humour.
John the Panasonics are pretty good and much more reliable than the ST.
I have used Kenwood, Panasonic, ST, HP and AP along with sound cards and software. I still own an HP 339 and 3562 but once you get a few good tests programmed on the AP it becomes hard to live without. I have both system One and Two dual domain and they are the go to standard. The computer screen becomes the knobs and is easier than my new Tek scope where you can't see all the settings
.
You can get a used One for $1500 and up replace the electrolytics caps and recalibrate it full manuals and calibration are online.
I have used Kenwood, Panasonic, ST, HP and AP along with sound cards and software. I still own an HP 339 and 3562 but once you get a few good tests programmed on the AP it becomes hard to live without. I have both system One and Two dual domain and they are the go to standard. The computer screen becomes the knobs and is easier than my new Tek scope where you can't see all the settings
.You can get a used One for $1500 and up replace the electrolytics caps and recalibrate it full manuals and calibration are online.
John the Panasonics are pretty good and much more reliable than the ST.
I have used Kenwood, Panasonic, ST, HP and AP along with sound cards and software. I still own an HP 339 and 3562 but once you get a few good tests programmed on the AP it becomes hard to live without. I have both system One and Two dual domain and they are the go to standard. The computer screen becomes the knobs and is easier than my new Tek scope where you can't see all the settings
You can get a used One for $1500 and up replace the electrolytics caps and recalibrate it full manuals and calibration are online.
The tricky part is the interface card, which Ap stopped selling for a while. I believe a version is available now for about 600US which has a USB interface. Since my XP-running "mainframe" crashed badly recently I may have to spring for the USB interface to be back in business with my borrowed SYS2322.
Thanks everyone for your input. Wayne, especially thanks for your input, because you have an HP339 and an HP3562. I am normally using a ST1700 with an HP3563. I am not looking to measure that much 'deeper' IF I lose realistic conditions where a connecting cable might be used.
The AP, for me, is not user friendly, and has lousy output graphs. What is the point of precise measurement, without good output graphs? So far the graphs that have been sent to me by Demian and Constellation are virtually uninterpretable to any resolution. I miss the old graph paper, it was SO MUCH BETTER!
The AP, for me, is not user friendly, and has lousy output graphs. What is the point of precise measurement, without good output graphs? So far the graphs that have been sent to me by Demian and Constellation are virtually uninterpretable to any resolution. I miss the old graph paper, it was SO MUCH BETTER!
Mr. Curl with all due respect I have ti disagree. Audio Precision is king. I was so impressed by what it can do that I am going to get one for work.
You should take a look at the new models.................the closest thing to sex (in the measurement field that is).
Your humble servant,
Jam
You should take a look at the new models.................the closest thing to sex (in the measurement field that is).
Your humble servant,
Jam
???
The AP graph was pretty clear with .01 dB resolution. The plot from the Boonton was similar printed from Excel so infinitely scaleable. What do you want to see? The pencil scratches? I have a pen plotter that can be connected to the Boonton. (Talk about boat anchor.)
Scott
Eddy current inspection detects work hardening on metals.
It shows a decreases in conductivity with work hardening, with copper too. You guessed right.
It also readily shows the thickening of skin depth (where ac currents flow) due to reduction of conductivity.
Thus, using frequency sweeping, the depth profile of work hardening can reliably be reported.
(Rubber mallet blows, does work harden copper).
DF96
Annealing means thermal relaxation of built-up strains and this is achieved by careful heat treatment.
Work hardening means building these strains-up.
And now it’s a good time for some cascaded speculative questions.
1) Does the ac electromagnetic wave while passing along electrical conductors exercise real (mechanical) stresses on the conducting material (assume non-ferromagnetic)?
2) If answer to 1) above is yes, these stresses will effect mechanical strains in the material.
What provides a detailed indication of the cause-effect mechanical phenomenon, is the stress-strain diagram for each metal or alloy.
A single-number relevant indication is the Modulus of Elastisity “E” for each material.
Lower “E” means lower strain (effect) for given applied stress (cause).
Below is a list for some metals
Material------Mod. Of Elast. "E"(Gpa)-----Electr. Resistivity (x10-8 Ohm.m)
Copper-------------117.2--------------------1.673
(annealed)
Gold----------------74.46--------------------2.35
Silver---------------72.39--------------------1.59
Aluminum------------68.95--------------------2.655
Tin------------------41.37-------------------11.0
Lead----------------13.79-------------------20.6
Mercury-------------( )----------------------98.4
3) Without dealing now with all the consequences of these build up strains, is there a merit in considering modulus of elastisity as well (apart from electr. resistivity) when choosing materials for conductors?
“Sound signature” of silver wires?
George
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