RayTek Thermalert ET Series, Operator'S Manual, Page: 20 / 33

2-10 Thermalert ET Series Operator's Manual
Electrical Connections
Color Connector Pin Function
Red 1 12 VAC supply
Black 2 12 VAC supply
Green 3 (-) 4-20 mA output
White 4 (+) 4-20 mA output
Uninsulated None Cable shield to earth
ground
2.3.2 Current Output Models
These sensors provide a 4-20 milliamp linear current output. These calibrated signals
may be interfaced to any controller, data logger, indicator, computer I/O, etc., requir-
ing a 4-20 mA linear current input. Note that four (4) wires are required: two (2) for
the calibrated linear signal and two (2) for the power supply.
Installation Checklist
1. The “power on” LED should be lit when power is supplied.
2. The Average and Peak Hold controls should be turned fully counter-clockwise.
3. Set a digital voltmeter to measure at least 20 mA and connect it to the output
(white [+], green [-]), and make sure the emissivity is less than 1.00.
4. Aim the sensor at objects with different temperatures. The meter will respond to
these changes.