For example, if the input is exactly 0.0000 and readout shows –0.0011,
0_ADJ should be adjusted by adding 0.0011 to it.
2.
Connect a 100
Ω
resistor (10 ppm accuracy) to the input and measure its
resistance. Note the average error in the measurement. Adjust the
100_ADJ parameter by subtracting the measured error. For example, if
the input is exactly 100.0000
Ω
and the readout shows 100.0295
Ω
,
100_ADJ should be adjusted by subtracting 0.0295 from it.
3.
Connect a 400
Ω
resistor (10 ppm accuracy) to the input and measure its
resistance. Note the average error in the measurement. Adjust the
400_ADJ parameter by subtracting the measured error. For example, if
the input is exactly 400.0000
Ω
and the readout shows 399.9913
Ω
,
400_ADJ should be adjusted by adding 0.0087 to it.
4.
Record the date with the calibration date parameter.
5.
Verify the accuracy at 0
Ω
, 25
Ω
or 50
Ω
, 100
Ω
, 200
Ω
, and 400
Ω
on se-
lected channels. Verify at least one resistance on each channel. The accuracy
must be within the short-term accuracy given in the specifications.
6.
Set the wiring configuration of both rows to three-wire (see Section
9.3.1). Verify the accuracy with at least one resistance on each channel.
The accuracy must be within the short-term accuracy plus the additional
three-wire uncertainty as given in the specifications.
9.4.4
Calibration Procedure (2568)
The calibration procedure for the 2568 Module is the same as the 2562 except
the parameters 0_ADJ, 1K_ADJ, and 4K_ADJ are used to calibrate the mea-
surement at 0
Ω
, 1K
Ω
, and 4K
Ω
respectively.
131
9 2562/2568 PRT Scanner Module
Calibration
