Apogee infrared radiometers are the most accurate non-contact temperature sensors available anywhere. The SI-131 has a 14 degree half angle field of view. The sensor has tinned leads for connecting to a datalogger. Applications include measuring the temperatures of road surfaces, plant canopies, and soil, snow and water surfaces. 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.
If you are using any SI-100 series sensor with Campbell Scientific Dataloggers, please view the three notices from Campbell Scientific and Apogee to the right.
Model SI-131 FOV = 14.0°
The SI-100 series sensors measure the temperatures of road surfaces, plant canopies, and soil, snow and water surfaces.
• Measures surface temperature rapidly
• Calibrated target temperature range from -30 to 65°C
• Uncertainty of 0.2°C (95% confidence)
• 8-14 µm germanium atmospheric window
• Radiation shield included
• Multiple field of view (FOV) options
• Rugged and lightweight
Field of View (FOV) is reported as the half-angle of the apex of the cone formed by the target (cone base) and the detector (cone apex). The target is a circle from which 98% of the radiation being viewed by the detector is being emitted.
Approximate Sensitivity: | 20 µV per °C |
Output from Thermistor: | 0 to 2500 mV (typical, depends on input voltage) |
Input Voltage Requirement: | 2500 mV excitation (typical, other voltages can be used) |
Calibration Uncertainty (-20 to 65°C): | 0.2°C, when target and detector temperature are within 20°C |
Calibration Uncertainty (-40 to 80°C): | 0.5°C, when target and detector temperature are different by more than 20°C |
Measurement Repeatability: | < 0.05°C |
Stability (Long-term Drift): | less than 2% change in slope per year when germanium filter is maintained in a clean condition |
Response Time: | 0.2s |
Field of View: | 14° half angle |
Spectral Range: | 8 to 14 µm; atmospheric window |
Operating Environment: | -55 to 80°C, 0 to 100% relative humidity (non-condensing) |
Dimensions: | 2.3 cm diameter and 6.0 cm length |
Mass: | 190g (with 5m of lead wire) |
Cable: | 5m of four conductor, shielded, twisted-pair wire. Additional cable available in multiples of 5m. Santoprene rubber jacket (high water resistance, high UV stability, flexibility in cold conditions). Pigtail lead wires. |
Warranty: | 4 years |