7
1.1.3
The radiometer Temperature connector (T)
The temperature connector of the CNR 4 carries the signals for the PT-100 and Thermistor. The PT-100 and
Thermistor have identical accuracy, the reason for selecting one or the other is mainly the data logger involved. The
Pt-100 temperature sensor has 4 wires, two for the measuring current and two for measuring the voltage over the
resistor (100 Ohm @ 0 °C) . In this way the measurement accuracy is minimally affected by the cable length. The
thermistor has a higher impedance of 10 kOhm and is therefore less influenced by cable length but has no
compensation for it. The shield of the cable is twisted together and covered with a black sleeve. If the CNR 4 (rod)
is grounded to the mast it is advised not to connect the shielding on the data logger side. This might cause ground
loops and offsets in the signal.
Figure 1.3 The temperature connections of the CNR 4. The instrument has one (4-wire) Pt-100 output and a
Thermistor with a 2-wire connection.
CNR 4 NET RADIOMETER
•
TEMPERATURE
6 WIRE CABLE • 6-ADRIGES KABEL • CÂBLE 6 FILS • CABLE DE 6 CONDUCTORES
7
8
5
3
4
6
Grey
Grau • Gris • Gris
Combined
Kombiniert
Combiné
Combinado
Pt-100
Standard
Standard
Etalon
Estándar
Combined
Kombiniert
Combiné
Combinado
Brown
Braun • Brun • Marrón
Green
Grün • Vert • Verde
Yellow
Gelb • Jaune • Amarillo
White
Weiss • Blanc • Blanco
Thermistor
Standard
Standard
Etalon
Estándar
Black
Schwarz • Noir • Negro
1
2
3 4
5
6
7
8
Ground *
Erde
Terre
Tierra
Housing
Gehäuse
Boîte
Cubierta
Shield
Abschirmung
Protection
Malla
