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4300C User Manual
The variation of resistance (ΔR) divided by the initial resistance (R
), is
0
equal to the temperature coefficient of the material (α) multiplied by the
variation of temperature (ΔΤ).
���� − ����
Expressed in terms of the resistance:
= ���� ( ���� − ����
)
[ 1 + ���� ( ���� − ����
)]
���� = ����
0
����
0
0
0
0
or
To better understand our uses of the equation, we will now express it in
terms of our application.
[ 1 + ���� ( ����
)]
����
= ����
− ����
����
����
����
����
Where R
is the compensated value, R
is the measured resistance, T
is
M
C
A
the ambient temperature and T
is the temperature reference. The
R
����
compensated resistance is therefore calculated as follows:
����
=
����
1 + ���� ( ����
)
− ����
����
����
����
The user can select from a list of temperature coefficients and
temperature references. The list is based on the most commonly used
values. The user can also customize these settings with unique values.
Once the temperature coefficient and the temperature reference are set,
the instrument's task is to measure the load resistance and the ambient
temperature. After all the variables are determined, the 4300C
automatically calculates the compensated resister value.
Here is an example of the equation.
Let's assume that we are measuring a copper wire, and we wish to know
the resistance value at a temperature of 20°C. The temperature
coefficient of copper is 0.003931Ω/°C.
1
If the load measures 1.0000Ω and the ambient temperature is 22.5°C:
����
=
= 0.9903Ω
1 + 0.003931 ( 22.5 − 20 )
����
The value of the load at 20°C would be 0.09903Ω.
4-2
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