M&C TechGroup ECP3000 Operator's manual - Manual (Page 20)

20
Gas sampling and gas conditioning technology 3-1.1-ME
18 CHECKING THE TEMPERATURE SENSOR
The ECP .000 cooler temperature sensor is a PT100 element as from serial numbers 95... . There
are two methods for checking the PT100 element, as follows:
1. Voltage method
In order to check the sensor for the cooler currently in operation, the actual voltage at the
corresponding measuring sockets
must be measured (see ‘Temperature Setting and Control’). The
following figure shows the voltage characteristics in relation to temperature. If the measured voltage is
inside the shaded area, the sensor is defective and must be replaced.
°C
V
o
lt
a
g
e
-3
-2
-1
0
1
2
3
4
-30 -20 -10 0 10 20 30 40
Figure 6 Voltage in relation to the temperature of the cooler
2. Resistance method
In this case the sensor must be disconnected from pins X5/3+4 at the ECP automatic control board
and removed from the cooling block. When measuring the resistance of the PT100 element, this must
be proportional to the ambient temperature. The resistance-temperature characteristics are shown in
the figure below.
°C
Ohm
95
97
99
101
103
105
107
109
111
113
115
117
-10 0 10 20 30 40
Figure 7 Resistance temperature characteristics of the PT100 temperature sensor