White
: High side of differential channel (positive
thermopile lead)
Black
: Low side of differential channel (negative
thermopile lead)
Green
: Single-ended channel (positive thermistor lead)
Blue
: Analog ground (negative thermistor lead)
Red
: Excitation channel (excitation for thermistor)
Clear
: Shield/Ground
OPERATION AND MEASUREMENT
The SIL-111 radiometer outputs two signals: a voltage from the thermopile radiation detector (proportional to the
radiation balance between target and detector) and a voltage from the thermistor (proportional to the magnitude
of the excitation voltage and resistance of thermistor). The voltage output from the thermopile is an electrically-
isolated bipolar (polarity is dependent on temperature difference between sensor and target) signal in the
microvolt range and requires a high-resolution differential measurement. The voltage output from the thermistor
can be measured with a single-ended measurement. In order to maximize measurement resolution and signal-to-
noise ratio, the input range of the measurement device should closely match the output range of the infrared
radiometer.
DO NOT connect the thermopile (white and black wires) to a power source. The detector is self-
powered and applying voltage will damage it.
Only the red wire should be connected to a power source.
Wiring for SIL-111
