SI-421-SS: SDI-12 Digital Output Narrow Field of View Infrared Radiometer Sensor

The SI-421 has an SDI-12 digital output. The sensor has an 18° half-angle field of view and a response time of 0.1 seconds.

  • Product Name:SI-421-SS: SDI-12 Digital Output Narrow Field of View Infrared Radiometer Sensor
  • Item No.:SI-421-SS: SDI-12 Digital Output Narrow Field of View Infrared Radiometer SensorSI-421-SS: SDI-12 Digital Output Narrow Field of View Infrared Radiometer Sensor
  • Manufacturers:Apogee
  • Country of Origin:USA

The SI-421 has an SDI-12 digital output. The sensor has an 18° half-angle field of view and a response time of 0.1 seconds. Typical applications include plant canopy temperature measurement for use in plant water status estimation, road surface temperature measurement of determination of icing conditions, and terrestrial surface (soil, vegetation, water, snow) temperature measurement in energy balance studies. Sensor includes IP67 marine-grade stainless-steel cable connector 30 cm from head to simplify sensor removal and replacement for maintenance and recalibration.

Input Voltage Requirement    4.5 to 24 V DC

Current Draw    0.6 mA (quiescent), 1.3 mA (active)

Measurement Range    -60 to 110 C (uncertainty has been determined for ranges below)

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    Less than 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    0.6 s, time for detector signal to reach 95 % following a step change, fastest data transmission rate for SDI-12 circuitry is 1 s

Field of View    18° half-angle

Spectral Range   8 to 14 µm; atmospheric window

Operating Environment    -55 to 80 C; 0 to 100 % relative humidity (non-condensing)

Dimensions    23 mm diameter, 60 mm length

Mass    190 g (with 5 m of lead wire)

Cable    5 m of four conductor, shielded, twisted-pair wire with TPR jacket (high water resistance, high UV stability, flexibility in cold conditions), additional cable available

Warranty    4 years against defects in materials and workmanship