6.2 The Function and Observing Conditions of the Automated
One-Channel IR-Radiometer
This practice concerns studying, graduating and calibrating the IR-radiometer.
Certain details of construction are special cases. However, considered principles
of operation and construction are inherent features in general for IR-radiometers.
Thus let’s consider the interaction between separate units of the instrument without
concrete specification of elements.
The automated one-channel IR-radiometer used in this teaching practice is
fabricated for remote measurement of the temperature of water surface (or other
surface with known emissivity) from the aircraft or helicopter board. The instrument is aimed to nadir observation in atmospheric window 8–13 mm. Space
scanning is done by observational platform moving.
The instrument is compiled from two parts: the optical unit and the unit for
processing signal. The optical unit can be put in both hermetic sealed and nonhermetic compartment of aircraft or helicopter. The optical axis is vertical for nadir
observation.
Operating the instrument allows following variants:
(a) registering observational results in digital form with indicators consisting from light-emitting
diodes;
(b) outputting the signal in digital form to computer (this option is used in laboratory module);
(c) outputting the signal in analog form (1, . . ., 5 V) for registering with the analog recorder.
Normal conditions for the processing unit are follows:
(a) the air temperature is in ranges
288–298 K (15–25
C);
(b) the air relative humidity is in ranges
15–65% for pointed temperatures;
(c) the atmospheric pressure is in ranges
96–104 kPa (720–780 mmHg);
(d) the supply voltage is
215.6–224.4 V and the frequency is 50 Hz;
Working conditions for the processing unit are follows:
(a) the air temperature is in ranges
278–313 K (5–40
C);
(b) the atmospheric pressure is in ranges
96–104 kPa (720–780 mmHg);
(c) the supply is possible from both the alternating current with the frequency 49.5–50.5 Hz and
voltage in ranges 198–244 V or the direct current with the voltage in ranges 24–30 V.
Working conditions for optical unit (with turned on thermostats) are follows:
(a) the air temperature is in ranges
253–303 K (À20 to þ30)
C;
(b) the air relative humidity is in ranges
98% for temperature 303 K (30
C);
(c) the atmospheric pressure is in ranges
33–104 kPa (250–780 mmHg).
Limiting conditions for transportation the instrument are:
(a) the air temperature is in ranges
253–333 K (À20 to þ60)
C;
(b) the air relative humidity is in ranges
99% for temperature 303 K (30
C);
56
6 Construction and Operation of the Automated One-Channel IR-Radiometer
One-Channel IR-Radiometer
This practice concerns studying, graduating and calibrating the IR-radiometer.
Certain details of construction are special cases. However, considered principles
of operation and construction are inherent features in general for IR-radiometers.
Thus let’s consider the interaction between separate units of the instrument without
concrete specification of elements.
The automated one-channel IR-radiometer used in this teaching practice is
fabricated for remote measurement of the temperature of water surface (or other
surface with known emissivity) from the aircraft or helicopter board. The instrument is aimed to nadir observation in atmospheric window 8–13 mm. Space
scanning is done by observational platform moving.
The instrument is compiled from two parts: the optical unit and the unit for
processing signal. The optical unit can be put in both hermetic sealed and nonhermetic compartment of aircraft or helicopter. The optical axis is vertical for nadir
observation.
Operating the instrument allows following variants:
(a) registering observational results in digital form with indicators consisting from light-emitting
diodes;
(b) outputting the signal in digital form to computer (this option is used in laboratory module);
(c) outputting the signal in analog form (1, . . ., 5 V) for registering with the analog recorder.
Normal conditions for the processing unit are follows:
(a) the air temperature is in ranges
288–298 K (15–25
C);
(b) the air relative humidity is in ranges
15–65% for pointed temperatures;
(c) the atmospheric pressure is in ranges
96–104 kPa (720–780 mmHg);
(d) the supply voltage is
215.6–224.4 V and the frequency is 50 Hz;
Working conditions for the processing unit are follows:
(a) the air temperature is in ranges
278–313 K (5–40
C);
(b) the atmospheric pressure is in ranges
96–104 kPa (720–780 mmHg);
(c) the supply is possible from both the alternating current with the frequency 49.5–50.5 Hz and
voltage in ranges 198–244 V or the direct current with the voltage in ranges 24–30 V.
Working conditions for optical unit (with turned on thermostats) are follows:
(a) the air temperature is in ranges
253–303 K (À20 to þ30)
C;
(b) the air relative humidity is in ranges
98% for temperature 303 K (30
C);
(c) the atmospheric pressure is in ranges
33–104 kPa (250–780 mmHg).
Limiting conditions for transportation the instrument are:
(a) the air temperature is in ranges
253–333 K (À20 to þ60)
C;
(b) the air relative humidity is in ranges
99% for temperature 303 K (30
C);
56
6 Construction and Operation of the Automated One-Channel IR-Radiometer