9.4.2
Front-Panel Access
The calibration parameters 0_ADJ, 100_ADJ, and 400_ADJ can be adjusted to
optimize the accuracy. They can be accessed from the front panel of the 1560
using the
CAL DEVICE
function in the
MODULE
soft-key menu (see Sec-
tion 5.4.3). Select the PRTS device. A window appears showing the calibration
parameters for the device.
CALIBRATE DEVICE: PRTS
0 ADJ: 0.0
100 ADJ: 0.0
400 ADJ: 0.0
CAL DATE: 09-21-95
SER NUM: A31123
For the 2562/2568 PRT Scanner module the list of parameters includes 0_ADJ,
100_ADJ, and 400_ADJ as described above. The list also includes the calibra-
tion date (CAL DATE) parameter, used to record the date the module was cali-
brated, and the serial number (SER NUM) parameter, used to record the serial
number of the module. New values can be entered for the parameters using the
numeric buttons and pressing
ENTER
. The
UD
buttons can be used to move
between parameters.
9.4.3
Calibration Procedure (2562)
Calibration requires adjustment of the 0_ADJ, 100_ADJ, and 400_ADJ param-
eters at three specific input resistances. If the resistances used are approxi-
mately 0
Ω
, 100
Ω
and 400
Ω
respectively the adjustments are independent and
the procedure is simple. The order in which the adjustments are performed is
important. The adjustment of the 400_ADJ parameter must be done last as the
adjustments of 0_ADJ and 100_ADJ affect the measurement at 400
Ω
but
400_ADJ does not affect the measurements at 0
Ω
or 100
Ω
. Any channel can be
used for calibration. Set the conversion type to R(
Ω
) to display resistance (see
Section 5.2.1.1). The calibration should be performed with four-wire connec-
tion and with the wiring configuration set up for four-wire (see Section 9.3.1).
The accuracy required of the resistance standards is 1/4 of the instrument accu-
racy; that is ±0.00025
Ω
at 0
Ω
, ±0.001
Ω
(10 ppm) at 100
Ω
, and ±0.004
Ω
(10
ppm) at 400
Ω
. The recommended procedure is as follows:
1.
Connect a 0
Ω
resistor to the input and measure its resistance. If a short-
ing wire is used the wire should run from pin 3 from the left to pin 4 to
pin 5 then back across to pin 2. Note the average error in the measure-
ment. Adjust the 0_ADJ parameter by subtracting the measured error.
1560 Thermometer Readout
User’s Guide
130
