functions. A diagram of the front panel is shown in Figure 17. The primary
components are described below.
Output
The rightmost terminals are used to connect the scanner to the Probe 1 mea-
surement input of the 1575 Thermometer. The arrangement of the four Output
terminals on the scanner corresponds to that of the Probe 1 input terminals and
should be connected accordingly (see Section 10.3.1.1).
Channel Inputs
Each of the ten channels has four terminal posts with which a probe is con-
nected. The red and black current terminals (“C+” and “C-”) supply current to
the probe. The “+” and “-” indications are only for reference; the polarity is ac-
tually periodically reversed. The red and black potential terminals (“P+” and
“P-”) are used to sense the voltage on the probe.
Guard Connector
The guard or shield of the probe cable can be connected to the “Guard” termi-
nal. If the guard is used, the Output guard terminal of the scanner should be
connected to the Probe 1 guard terminal of the 1575. All of the guard terminals
of the inputs are wired to the output guard terminal; they are not switched. Us-
ing a guard may help to reduce the effects of interference in electrically noisy
environments.
Channel Select
The ten front panel buttons allow you to select the channel for measurement.
The channel can also be selected by the 1575 Thermometer.
117
10 2575 Scanner (optional)
Parts and Controls
Figure 17
2575 Scanner Front Panel
