User Manual

OPERATION AND MEASUREMENT
Connect the sensor to a measurement device (meter, datalogger, controller) capable of measuring and displaying a
4-20 mA signal. 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 quantum sensor. DO NOT connect the sensor
to a power source greater than 24 V DC.
VERY IMPORTANT: Apogee changed the wiring colors of all our bare-lead sensors in March 2018 in
conjunction with the release of inline cable connectors on some sensors. To ensure proper connection to your
data device, please note your serial number or if your sensor has a stainless-steel connector 30 cm from the
sensor head then use the appropriate wiring configuration listed below. With the switch to connectors, we also
changed to using cables that only have 4 or 7 internal wires. To make our various sensors easier to connect to
your device, we clip off any unused wire colors at the end of the cable depending on the sensor. If you cut the
cable or modify the original pigtail, you may find wires inside that are not used with your particular sensor. In
this case, please disregard the extra wires and follow the color-coded wiring guide provided.
Wiring for SQ-214 and SQ-224 with Serial Numbers 7603 and above
Wiring for SQ-214 and SQ-224 within Serial Number range 0-7602
Red: Input power
Black: Input ground
Clear: Shield/ground
Green: Signal ground
White: 4-20 mA signal output
Black: Ground (for sensor signal and input power)
Red: Input power (7-24 V DC)
White: 4-20 mA signal output
Clear: Shield/Ground