Measurement of surface temperature is a crucial component of energy transfer. Accurate measurement of the leaf-to-air temperature gradient is essential to the determination of the transpiration rate and stomatal conductance in both single leaves and plant canopies. This gradient is often less than 3oC, which means that leaf temperature should be measured to within 0.3oC, which means that leaf temperature should be measured to within 0.3oC. TO achieve this accuract, the Apogee Instruments precision IRT's use two, type-K Thermocouple outputs. The primary thermocouple is used to measurethe sensor body temperature. Errors caused by changes in the sensor body temperature are corrected in software with a 12-step subroutine orginally designed for Campbell Scientific dataloggers.
Specifications
Power Supply Requirements: None: self-powered
Operating Environment: Highly water resistant, designed for continuous outdoor use
Optimum temperature range is the calibrated range, or -10 oC to 55 oC (based on sensor body temperature)
Accuracy:
Model IRTS-P / Model IRTS-P3 = ± 0.50 oC
Model IRTS-Pb / Model IRTS-P3b = ± 0.24 oC
Model IRTS-Pc / Model IRTS-P3c = ± 0.15 oC
± 0.1 oC when sensor body and target are at the same temperature - all models
Repeatability: 0.05 oC from 15 to 35 oC
Mass: Less than 100 grams
Dimensions: 6 cm long by 2.3 cm diameter
Response Time: Less than 1 second to changes in target temperature
Output Signal: 2, type-K, twisted, shielded pair thermocouple outputs (4.5 meters each), one for target temperature, one for sensor body temperature. Designed for use with Campbell Scientific data loggers. Compatible with most data acquisition systems.
Optics: Silicon lens
Wavelenght Range: 6.5 to 14 µm
Field of View: The FOV of infrared sensors is typically specified as the half angle, but all sensors are center-weighted and there is not a sharp cut-off at the edges. The half angle of the IRTS-P is 28.5oC.
