The Bently Nevada 3500/46M Hydro Monitor is a four-channel instrument that accepts input from proximity, seismic and air gap sensors. The monitor conditions the signal to provide vibration as well as position measurements and compares the conditioned signals with user-programmable alarms .

Hydro Radial Vibration channels combine the shaft gap movement with the NX amplitude to provide a measurement to alarm on shear-pin failure. The monitor accepts 1 to 4 signals and features front panel LEDs for OK, TX/RX, and Bypass status indication .

Power consumption is 7.7 watts typical, with multimode positive input I/O at 50 kΩ. Approvals are available including CSA/NRTL/C (Class 1, Division 2) and ATEX/IECEx/CSA (Class 1, Zone 2). The monitor is designed for hydro turbine applications where monitoring of radial vibration and position is critical for machinery protection .