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SIF-121: High Speed, Narrow Field of View Infrared Radiometer


Product Description

The SIF-121 is a fast response model infrared radiometer with a 0.2 second response time. The analog sensor is un-amplified and has a voltage output. The sensor has a 18° half-angle field of view. 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.


Approximate Sensitivity

10 μV per C

Output from Thermistor

2500 mV excitation (typical, other voltages can be used)

Input Voltage Requirement

0 to 2500 mV (typical, depends on input voltage)

Calibration Uncertainty (-20 to 65 C)

0.2 C

Calibration Uncertainty (-40 to 80 C)

0.5 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 clean condition

Response Time

0.2 s, time for detector signal to reach 95 % following a step change

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)


23 mm diameter, 60 mm length


190 g (with 5 m of lead wire)


5 m of shielded, twisted-pair wire. Additional cable available in multiples of 5 m. Santoprene rubber jacket (high water resistance, high UV stability, flexibility in cold conditions). Pigtail lead wires.


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Dianjiang Group Limited
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Email: Dianjiang_HK@yahoo.com.hk   Hongkong@Dianjiangtech.com
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