Xylem CR500 CIRCULAR CHART RECORDERS - Manual (Page 11)

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Thermocouple Input Wiring
Thermocouple input connections are shown in the following figures. The correct type of
thermocouple extension lead-wire or compensating cable must be used for the entire
distance between the unit and the thermocouple, ensuring that the correct polarity is
observed throughout. Splices in the cable should be avoided, if possible. A Ferrite bead is
supplied with the CR500 recorder to provide additional isolation against input noise.
Input wiring should be wrapped around the core before wiring to the recorder inputs. See
Figure 2.3.
If the length of thermocouple plus the extension wire is too long, it may affect the
temperature measurement. A 400 ohms K type or a 500 ohms J type thermocouple lead
resistance will produce approximately 1 degree C temperature error.
Figure 2.4 Single Pen Ink Style Inputs