Campbell CNR4, Инструкция по эксплуатации

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CNR4 Net Radiometer
20
The thermistor measurement is calculated by the datalogger, using the Half-
Bridge Measurement instruction, which requires one voltage excitation and
one single-ended analog channel.
Alternatively, you can use the Pt-100 to make the temperature measurement. In
order to make the temperature measurement, using the Pt-100 sensor, you will
need one current excitation channel, and one differential analog channel.
TABLE 8–2 shows the Pt-100 resistance values as a function of temperature.
Please refer to Appendix B.4 , CR3000 Program for Measuring Pt-100
Temperature Sensor
(p. B-10)
, for a sample program to measure Pt-100.
TABLE 8–2. Resistance values versus CNR4’s Pt–100 temperature in °C
Temperature
[°C]
Resistance
[
Ω
]
Temperature
[°C]
Resistance
[
Ω
]
Temperature
[°C]
Resistance
[
Ω
]
–30
–29
–28
–27
–26
–25
–24
–23
–22
–21
–20
–19
–18
–17
–16
–15
–14
–13
–12
–11
–10
–9
–8
–7
–6
–5
–4
–3
–2
–1
88.22
88.62
89.01
89.40
89.80
90.19
90.59
90.98
91.37
91.77
92.16
92.55
92.95
93.34
93.73
94.12
94.52
94.91
95.30
95.69
96.09
96.48
96.87
97.26
97.65
98.04
98.44
98.83
99.22
99.61
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
100.00
100.39
100.78
101.17
101.56
101.95
102.34
102.73
103.12
103.51
103.90
104.29
104.68
105.07
105.46
105.85
106.24
106.63
107.02
107.40
107.79
108.18
108.57
108.96
109.35
109.73
110.12
110.51
110.90
111.28
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
111.67
112.06
112.45
112.83
113.22
113.61
113.99
114.38
114.77
115.15
115.54
115.93
116.31
116.70
117.08
117.47
117.85
118.24
118.62
119.01
119.40
119.78
120.16
120.55
120.93
121.32
121.70
122.09
122.47
122.86
8.4 Calculation of Albedo
Albedo is the ratio of reflected short-wave radiation to incoming short-wave
radiation. This unitless value ranges between 0 and 1. Typical values are 0.9
for snow, and 0.3 for grassland. To determine the albedo, the measured values
of the two pyranometers are used. Do not use the measured values when the