4. To repeat the procedure above the desired point of the water surface ten times
with recording results of radiometer and reference thermometer.
5. To repeat the procedure at other 10–15 points of the surface for other surface
temperatures in ranges 0–30
C.
6. To correct the tuning IR-radiometer if temperature recording by radiometer and
reference thermometer distinguish more than 0.3 К.
Remark. Recording by radiometer might exceed thermometer recording by
0.5–0.8
C in the temperature range 0–9
C, because of the warm skin film on
the surface that is in contact with the warm laboratory air. By contrast in the
temperature range 16–30
C radiometer recording might be lower by 0.5–1 К than
thermometer recording owing to surface skin film heat losses through the
evaporation.
The Fig. 6.1 demonstrates the plot of testing results. On the abscissa recordings
by IR-radiometer (Tr) are plotted and on the ordinate the difference (dT) between
remote by radiometer (Tr) and contact by thermometer (Ts) recordings are plotted.
The Table 6.1. presents the similar data in tabulated view. The special file “kalib1.
dat” with calibrating values can be used for quantitative analysis during
observation.
10.00
20.00
30.00
40.00
Tr: data from IR rad; [C]
-3.00
-2.00
-1.00
0.00
1.00
dT = Ts - Tr; [C ]
Fig. 6.1 Example of the IR-radiometer calibration
6.5 Preparing the IR-Radiometer to Operation
59
with recording results of radiometer and reference thermometer.
5. To repeat the procedure at other 10–15 points of the surface for other surface
temperatures in ranges 0–30
C.
6. To correct the tuning IR-radiometer if temperature recording by radiometer and
reference thermometer distinguish more than 0.3 К.
Remark. Recording by radiometer might exceed thermometer recording by
0.5–0.8
C in the temperature range 0–9
C, because of the warm skin film on
the surface that is in contact with the warm laboratory air. By contrast in the
temperature range 16–30
C radiometer recording might be lower by 0.5–1 К than
thermometer recording owing to surface skin film heat losses through the
evaporation.
The Fig. 6.1 demonstrates the plot of testing results. On the abscissa recordings
by IR-radiometer (Tr) are plotted and on the ordinate the difference (dT) between
remote by radiometer (Tr) and contact by thermometer (Ts) recordings are plotted.
The Table 6.1. presents the similar data in tabulated view. The special file “kalib1.
dat” with calibrating values can be used for quantitative analysis during
observation.
10.00
20.00
30.00
40.00
Tr: data from IR rad; [C]
-3.00
-2.00
-1.00
0.00
1.00
dT = Ts - Tr; [C ]
Fig. 6.1 Example of the IR-radiometer calibration
6.5 Preparing the IR-Radiometer to Operation
59