WIKA A2G-60 Betriebsanleitung Seite 15

5. Commissioning, operation
5.2.1 Temperature probe (passive)
The instruments are designed to operate with safety extra-low voltage
(SELV). When wiring up the instruments, the technical specifications
for those instruments should be followed. Especially with passive
EN
temperature probes (e.g. Pt1000, etc.) with a 2-wire system, the lead
resistance of the supply line must be considered. If necessary, this
must be corrected in the connected electronics. Due to self-heating, the
measuring current affects the measurement accuracy; therefore, this
should not be greater than 1 mA.
When using long connection cables (and depending on the cross-
section used), the measuring result might be falsified due to a voltage
drop on the common GND line (caused by the supply current and
the lead resistance). In this case two GND lines must be laid to the
temperature probe, one for the sense current and one for the measuring
current.
2-wire 3-wire
WIKA operating instructions model A2G-60 15