Leaf and Bud Temperature Sensor FAQs

Leaf and bud temperature sensors should be mounted within or very near the plant canopy where frost detection is desired, so the simulated leaf and bud are in the same environment as the plant leaves and buds. Mounting the sensor with a slight downward slope or tilt on one side is recommended to minimize moisture/debris build-up on simulated leaf.

We recommend using an Apogee AM-220 Mounting Bracket to mount the sensor to a cross arm or pole. The AM-220 allows adjustment of the angle of the detector.

Apogee leaf and bud temperature sensors are weatherproof and are designed to be continuously deployed in outdoor conditions.

Apogee SF-110 leaf and bud temperature sensors yield two independent resistances that are proportional to simulated leaf and bud temperatures. A quick and easy check of functionality of the two thermistors can be accomplished with an ohmmeter. To check the simulated leaf circuit, connect the lead wires of the ohmmeter to the red and black wires from the detector. The resistance should read 10 kΩ (10,000 ohms) at 25 C. If detector temperature is less than 25 C, resistance will be higher. If detector temperature is greater than 25 C, resistance will be lower. Connect the lead wires of the ohmmeter to the black and blue wires from the detector. The resistance should read 24.9 kΩ, and should not vary. Connect the lead wires of the ohmmeter to the red and blue wires from the sensor. The resistance should be the sum of the resistances measured across the red and black wires, and black and blue wires (e.g., 10 kΩ plus 24.9 kΩ at 25 C). To check the simulated bud circuit, connect the lead wires of the ohmmeter to the white and green wires from the sensor. The resistance should read 10 kΩ at 25 C. If detector temperature is less than 25 C, resistance will be higher. If detector temperature is greater than 25 C, resistance will be lower. Connect the lead wires of the ohmmeter to the green and orange wires from the detector. The resistance should read 24.9 kΩ, and should not vary. Connect the lead wires of the ohmmeter to the white and orange wires from the sensor. The resistance should be the sum of the resistances measured across the white and green wires, and green and orange wires (e.g., 10 kΩ plus 24.9 kΩ at 25 C).

Yes, if properly spliced, the signal from the sensor is not affected by splicing on additional cable. Please check the Owner's Manual for details and limitations on adding cable. For information on how to create a proper waterproof splice, please visit our instructional webpage or watch our video. We offer custom cable lengths of our high quality cable and splice kits that can be ordered at the time of purchase or a later date.