PCIe/PXIe-6301 Series |
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3-wire RTD connection
In a 3-wire RTD configuration, AI+ terminal will output a precision current excitation,
500 µA to RTD sensor and flow back through the Ex- terminal and AI- terminal as
shown in Figure 4 . Since the voltage generated by the RTD connecting the AI+ terminal
and the voltage connected to the AI- terminal will cancel each other, this connection
can effectively eliminate the influence of the lead wire resistance, but in practical
applications, the resistance of the two lead wires is difficult to match completely, so
there will still be a certain degree of mismatch error.
Figure 4 3-wire RTD connection
