Two / Three / Four Wire Rtd-­Hookups; Figure 2.6 Two/Three/Four-­Wire Rtd Wiring Hookup A) Rtd-­1000 Ohm/Rtd-­500 Ohm; B) Rtd-­100 Ohm - Omega i Series User Manual

2.3.3 Two/Three/Four-­Wire RTD
(shown in bold lines) required to hookup a 2-­, 3-­ or 4-­wire RTD.
Figure 2.6 a) RTD-­100 ohm and
500 ohm Wiring
Hookup
The two-­wire connection is simplest method, but does not compensate for
lead-­wire temperature change and often requires calibration to cancel lead-­wire
resistance offset.
The three-­wire connection works best with RTD leads closely equal in
resistance. The device measures the RTD, plus upper and lower lead drop
voltage and the subtracts twice the measured drop in the lower supply
current lead producing excellent lead-­resistance cancellation for balanced
measurements.
The four-­wire RTD hookup is applicable to unbalanced lead resistance and
enables the device to measure and subtract the lead voltage, which produces
the best lead-­resistance cancellation.
Type menu (see Part 3).
If the input wires of the meter get disconnected or broken, it will display
+OPN
RTD. In this case the display shows
For safety purpose you may want to set up your alarm to be triggered
when input is open. See Alarm 1 & 2 Sections 3.2.6, 3.2.7 for details.
RTD (1000/500) 4-Wire
RTD (1000/500) 3-Wire
RTD (1000/500) 2-Wire
b) RTD-­100 ohm Wiring Hookup
"Input (-­) Open" message.
-‐OPN
8
RTD (100) 4-Wire
RTD (100) 3-Wire
RTD (100) 2-Wire