Running the cable through a conductive conduit provides additional shielding and increases immunity to EMI/RFI. For best results, the conduit should be grounded at both ends. As a general rule, the conduit is automatically grounded at the transmitter because it screws into the transmitter housing, which should be grounded. Ensuring the conduit is also grounded at the accelerometer end (and at points along the conduit run) reduces coupling of the interfering energy into the cable and propagating it along the cable into the accelerometer.
Figure 1 shows how to run the accelerometer through a conduit that is grounded on both ends. As a general rule, the transmitter housing itself is grounded through the base where it is mounted. Since the conduit is electrically connected to the transmitter housing, this effectively grounds the conduit at the transmitter end.
Grounding the conduit at the accelerometer end as well significantly reduces the possibility that energy due to EMI/RFI can be coupled into the accelerometer cable. When employing this method, minimize the length of cable that is outside of the conduit by running the conduit as close as reasonably possible to the point where the accelerometer is mounted to the equipment being monitored.
Figure 1. Grounded conduit
