Section 4: Basic DMM operation
Series 3700A System Switch/Multimeter Reference Manual
4-30
3700AS-901-01 Rev. D/June 2018
3-wire RTD connections
Shown below are 3-wire RTD connections to the Series 3700A. For a 3-wire RTD capable 40-channel
switching module, paired channels perform the 3-wire measurement. For example, the two input
leads of the RTD are connected to a primary channel (1 through 20), while only the LO sense lead is
connected to its paired channel (21 through 40). Channel 1 is paired to channel 21, channel 2 is
paired to channel 22, and so on.
The HI sense of the paired channels is not used for 3-wire RTD.
Figure 58: Three-wire RTD connections
Figure 59: Three-wire RTD switching module connections
4-wire RTD connections
Shown below are 4-wire RTD connections to the Series 3700A. For a 4-wire RTD capable 40-channel
switching module, paired channels are used to perform the 4-wire measurement. For example, the
two input leads of the RTD are connected to a primary channel (1 through 20), while the two sense
leads are connected to its paired channel (21 through 40). Channel 1 is paired to channel 21, channel
2 is paired to channel 22, and so on.
