Single Analog/Digital Inputs; Thermocouple; Resistance Thermometer (Rtd) - ABB SM500F User Manual

SM500F
Field mountable paperless recorder

2.4 Single Analog/Digital Inputs

2.4.1 Thermocouple

Use the correct compensating cable between the thermocouple and the terminals – see Table 2.1,
page 20.
Automatic cold junction compensation (ACJC) is incorporated but an independent cold (reference) junction
may be used.

2.4.2 Resistance Thermometer (RTD)

On applications requiring long leads it is preferable to use a 3-lead resistance thermometer.
If 2-lead resistance thermometers are used, each input must be calibrated to take account of the lead
resistance.
1 2 3 4
+ –
Voltage
1 2 3 4
3-lead RTD
*
Fig. 2.9 Single Analog/Digital Input Connections
Note. Analog/digital input terminal screws must be tightened to a torque of 0.5 Nm (4.5 lbf.in).
18
1 2 3 4
–
*
Current
1 2 3 4
W
4-lead RTD
2 Installation
1 2 3 4
–
Thermocouple
1 2 3 4
–
Digital Input
IM/SM500F Rev. Z