- Low cost, easy to install, leaf temperature sensors;
- Simply clip the sensor onto a leaf for long-term, low maintenance, field measurements;
- Ideal for scientific research or irrigation scheduling and monitoring;
- Measure a single leaf (LT-1T model) or the average of four leaves (LT-4T model);
- SDI-12 output and low power for remote field monitoring and IoT devices (LoRaWAN, NB-IoT).
The Leaf Temperature Sensor is a sub-miniature touch probe that measures absolute temperature of a leaf.
The lightweight stainless steel wire clip holds a high precision glass encapsulated thermistor, which is about millimeter in diameter. Small size of the probe and its special design provide almost negligible disturbance of the natural leaf temperature.
The thermistor is typically positioned on the underside of the leaf blade where it comes into equilibrium with the leaf's temperature. As the leaf transpires, through stomatal conductance or the loss of water vapour through tiny pores (stomata) on the leaf, the temperature of the leaf will be lower than ambient air temperature. Plants under low irrigation or drought stress will have a leaf temperature closer, or higher, than ambient air temperature.
The thermistor is connected to the clip by a thin 0.15 mm leads to minimize heat conduction and response time. All conductors are proofed to avoid corrosion under the wet operating conditions.
Every sensor is tuned and calibrated within the measurement range. The tolerance range is ±0.08 ℃ only.
LT-1T versus LT-4T Leaf Temperature Sensor Models
The LT-1T model has a single thermistor and leaf clip. The LT-1T model is ideal for smaller plants or plants with compact canopy.
The LT-4T models has four individual thermistors and leaf clips each with a 1m length cable. The LT-4T is ideally suited to larger plants or plants with a dense canopy. The four thermistors can be positioned randomly or via a stratified design across the canopy. For example, a thermistor can be installed on the north, south, east and west locations of the canopy; or bottom, middle and top of the canopy. The LT-4T averages the measurement from the four thermistors as a single reading output.
Ideal for Internet Enabled Devices and Remote Field Monitoring
The Leaf Temperature Sensor is ideal for IoT devices and remote field monitoring because:
- It operates via the SDI-12 protocol which is supported by a wide range of data loggers and telemetry units;
- It has low power requirements and can be supported off small batteries;
- It is quick to install (less than a minute) and ongoing maintenance is minimal.
The team at Implexx can provide data loggers and telemetry devices. Our international network of accredited dealers and agents also have a range of data acquisition options that may be unique to your specific location. Otherwise, we can assist in connecting our leaf temperature clips to your existing irrigation monitoring or data acquisition system.
|Measurement Range||−5 to 50 C|
|Thermistor + Leaf Clip Weight||1.6 grams|
|Contact Area of Thermistor||~ 1 mm2|
|Supply Voltage||5 to 24 VDC|
|Excitation Time||0.15 seconds|
|Cable Length Between Thermistor and Signal Conditioner||1 m|
|Cable Length Between Signal Conditioner and Data Logger||5 m (standard) | 60 m (maximum)|
Manual & Docs