Envco – Environmental Equipment

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 transpiration rate and stomatal conductance in both single leaves and plant canopies.

This gradient is often less than 1 C, which means that leaf temperature should be measured to within 0.2 C. To achieve this accuracy, the Apogee Instruments Infrared Radiometers correct for changes in the sensor body temperature with a subroutine designed for Campbell Scientific dataloggers.

The 8-14 µm window of the SI-111 and SI-121 corresponds to the atmospheric window in order to minimize the effects of water bands below 8 µm and above 14 µm.

Select either a standard (SI-111) or narrow (SI-121) field of view. These offer 22˚ and 18˚ half angles, respectively

Ordering Information
Model SI-111 Half-angle = 22.0˚
Model SI-112 Half-angle = 18.0˚