In semiconductor wafers it is used the "resistance of a square", that=0A=
is: if you have a square piece of semiconductor with two electrodes in=0A=
two opposite sides, the measured resistance is a constant, irrespective=0A=
of the measure of the side of the square.=0A=
=0A=
Bigger squares have more power dissipation capability.=0A=
=0A=
To make resistors with different values just make the areas rectangular.=0A=
=0A=
To me it seems that for water something similar could be used, such as=0A=
"resistance of a cube", using a cubic recipient with two opposite faces=0A=
being metallic electrodes.=0A=
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Isaac=0A=
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Em 9/9/2011 13:41, mark springer escreveu:=0A=
> unit resistivity per area/length=0A=
>=0A=
> resistance has to be ? expressed over a Volume. can you have=0A=
> dimensionless resistance that is not infinite? I do not see it=0A=
>=0A=
> On 9/9/11, mark springer <mbspringer133@gmail.com> wrote:=0A=
>> "At 25=B0C the accepted values with their uncertainties for=0A=
>> conductivity, =EA and its reciprocal, resistivity, =F1, are:=0A=
>> =EA =3D 0.05501 =B1 0.0001 =ECS/cm at 25.00 =B0C=0A=
>> =F1 =3D 18.18 =B1 0.03 M=D9=B7cm at 25.00 =B0C"=0A=
>>=0A=
>> Standardized Result:  18.18 M=D9=B7cm=0A=
>> unit resistivity per area/length.??=0A=
>> http://hypertextbook.com/facts/2006/SamTetruashvili.shtml=0A=
>>=0A=
>>=0A=
>>=0A=
>>=0A=
>> On 9/8/11, cdb <colin@btech-online.co.uk> wrote:=0A=
>>>  I've been looking at the specifications for a domestic water heater an=
d=0A=
>>> in=0A=
>>> the sales bumph they specify the minimum water resistivity required=0A=
>>> (2K795=0A=
>>> x inches or 1K1 x cm's). I've never seen such a specification before fo=
r=0A=
>>> this kind of water heater nor the unit resistivity per area/length.=0A=
>>>=0A=
>>> I can find no documents on the interrent apart from those referring to=
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>>> measurement devices for analytical purposes.=0A=
>>>=0A=
>>> Colin=0A=
>>> --=0A=
>>> cdb,   8/09/2011=0A=
>>>=0A=
>>> --=0A=
>>>=0A=
>>>=0A=
>>>=0A=
>>>=0A=
>>> colin@btech-online.co.uk=0A=
>>>=0A=
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