Maker Pro
Maker Pro

high-resistance wire 40kOhm per meter

M

Michael Koch

Jan 1, 1970
0
Tim,
Carbon-core "ignition wire" is about 5K ohms per foot.

yes, but the diameter is too big. I want to build several 3-axis sensors.

Michael
 
M

Michael Koch

Jan 1, 1970
0
Joerg,
Can't you make it from small snippets of regular very thin wire with,
say, a 0201 size or smaller 402 ohm resistor every centimeter and slide
it all into thin tubing?

That's a lot of work. At least the first meter from the sensor should
have high resistance. That means I need 4 meter wire for a 3-axis
sensor. And my idea was to have several 3-axis sensors mounted on a wood
frame, so that field homogeneity can be measured simultaneously at all
sensors. For example 3 x 3 x 3 = 27 sensors in a 1m^3 cube, each sensor
is 3-axis, --> 81 sensors total. That's only possible if cheap
high-resistance wire is available.

Michael
 
Joerg,


That's a lot of work. At least the first meter from the sensor should
have high resistance. That means I need 4 meter wire for a 3-axis
sensor. And my idea was to have several 3-axis sensors mounted on a wood
frame, so that field homogeneity can be measured simultaneously at all
sensors. For example 3 x 3 x 3 = 27 sensors in a 1m^3 cube, each sensor
is 3-axis, --> 81 sensors total. That's only possible if cheap
high-resistance wire is available.

Michael

wet string?
 
R

Rich Grise

Jan 1, 1970
0
the NIST E-field detector is built with high-resistance wire, about
40kOhm per meter. It's described here:
http://scott-inc.com/html/nist.htm

Does anybody know a source for this wire?

You can get 0.0031" OD nichrome wire at McMaster-Carr:
http://www.mcmaster.com/#catalog/115/3675

But you'll have to figure out the resistance per foot on your own.

Thinner wire is probably available - I just happened to know MMC has
it off the top of my head.

Good Luck!
Rich
 
M

Michael Koch

Jan 1, 1970
0
Joerg,
Michael, this just dawned on me, you might want to call Isabellenhuette
in Dillenburg, Germany (hey, I was in that town last March ...) and ask
about their ISA-Ohm wire. Not quite the 40k but almost 17k for the
really thin stuff:

That's very interesting, I think it's close enough to 40kOhm/m.

Thanks!

Michael
 
W

whit3rd

Jan 1, 1970
0
Hi,

the NIST E-field detector is built with high-resistance wire, about
40kOhm per meter. It's described here:http://scott-inc.com/html/nist.htm

Does anybody know a source for this wire?

The easiest source for resistance wire is thermocouple alloys (like
Constantan, for type J thermocouples, which was originally
a low tempco resistor wire). My tables show 56 gage as the finest
and that only has a tenth the resistance you want. It gets
brittle (and becomes a fuse more than a wire) if you try to
get thinner wire.

Some HV resistors are made with a buffer solution in vinyl tubing,
you could get a roll of capillary tubing and mix up your own
fill liquid.
 
Top