Setting Coefficients; Current; Device Setup Commands - Fluke 1560 Black Stack User Manual

1560 Thermometer Readout
User's Guide
9.3.3
9.3.4
9.3.5
128
shown in the specifications. Also, be aware that any difference between the
resistances of the lead wires directly affects accuracy.
Two-wire sensors are connected as shown in Figure 15. The shield, if used, is
connected to pin 1 on the left. One wire connects to both pins 2 and 3 from the
left. The opposite wire connects to both pins 4 and 5. Be sure to check that the
wiring configuration for that row is set to 4 as explained above! When using
two-wire sensors the 2562/2568 is unable to compensate for lead resistance.

Setting Coefficients

Once a PRT or SPRT probe is properly connected to the 2562/2568, the 1560
can read out its resistance. To display temperature accurately the 1560 must be
programmed with the characterization coefficients for the sensor. This is done
using the EDIT PROBE soft-key in the PROBE menu (see Section 5.2.1). The
coefficient values are normally provided with the probe on a calibration report.
Be sure to select the proper range for ITS-90 characterizations. If IEC-751
RTDs are used you may select the CVD conversion and use R0: 100, ALPHA:
0.00385, DELTA: 1.507, and BETA: 0.111.

Current

The 2562/2568 sources current to the sensor and measures the resulting voltage
across the sensor to determine its resistance. The current alternates every 0.5
seconds to reduce the effects of thermoelectric offsets. The normal current is
1.0 mA. The current can be changed to 1.4 mA to test self-heating effects using
the SET UP DEVICE function in the MODULE menu (see Section 5.4.2).
Change the CURRENT parameter from 1.0 to 1.4 and press ENTER.
The SET UP DEVICE function also allows access to two other parameters.
SAMP PER selects the sample period between 2 (normal) and 10 seconds. RES
RANGE sets the resistance range between AUTO ranging (normal), LOW
range, and HIGH range. The purpose of these options is mainly for trouble-
shooting and they should not need to be changed during normal operation.

Device Setup Commands

The SYST:MODn:DEVn:READ? and SYST:MODn:DEVn:WRIT commands
(see Sections 6.5.8.19 and 6.5.8.20) can be used to read or set the setup param-
eters for the 2562/2568 PRT Scanner Module. The device number of the PRT
Scanner Input Device is 1. The module number for the 2562/2568 module is its
position in the stack. For example, if the 1560 has four add-on modules, the
2562/2568 being second, the module number for the 2562/2568 is 2. Table 25