SYST:MOD2:DEV1:WRIT “WIRF”,4
Set the front-row configuration to
four-wire.
11.4
Calibration
This section explains the calibration procedure for the 2564 Thermistor Scan-
ner Module.
11.4.1
Calibration Parameters
Three adjustable parameters are used for calibration: 0_ADJ, 10K_ADJ, and
100K_ADJ. 0_ADJ directly affects the measurement at 0
Ω
. It has negligible ef-
fect at 10 k
Ω
but significant affect at higher resistances. 10K_ADJ directly af-
fects the measurement at 10 k
Ω
. It has negligible effect at 0
Ω
and
proportionately greater effect the higher the resistance. 100K_ADJ directly af-
fects the measurement at 100 k
Ω
. It has negligible effect at 0
Ω
and 10 k
Ω
with
greater effect the more the resistance deviates from 0
Ω
or 10 k
Ω
. Each of the
parameters has positive effect at their primary resistances: increasing the value
of the parameter increases the measured resistance. The default and theoreti-
cally normal value for each is 0.
11.4.2
Front-Panel Access
The calibration parameters 0_ADJ, 10K_ADJ, and 100K_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 THRS device. A window appears showing the calibration
parameters for the device.
143
11 2564 Thermistor Scanner Module
Calibration
Device Command
Parameter
Description
CURR
AUTO, 2, 10
Excitation current,
μ
A
WIRF
3, 4
Front-row wire
configuration
WIRR
3, 4
Rear-row wire
configuration
SAMP
2, 10
Sample period, seconds
ARNG
AUTO, LOW, HIGH
Resistance range
Table 27
Thermistor Scanner Module Commands
