The Bently Nevada 3500/42M Proximitor Monitor is a versatile 4-channel module within the 3500 Series machinery protection system, designed to accept input from both proximity and seismic transducers . It conditions these signals to provide a comprehensive suite of vibration and position measurements, comparing them against user-programmable alarm setpoints for continuous protection .

Using the 3500 Rack Configuration Software, the channels (programmable in pairs) can be configured to perform a wide range of functions . These include standard measurements like Radial Vibration and Thrust Position, as well as more specialized parameters such as Differential Expansion, Eccentricity, and REBAM (Radial Eccentricity Bearing Analysis Measurement). Furthermore, by accepting seismic inputs, it can also provide measurements for Acceleration, Velocity, and Shaft Absolute vibration, offering a complete picture of both relative and absolute machine motion .

The 3500/42M features a standard input impedance of 10 kΩ and consumes 7.7 watts of power. Its ability to handle both proximity and seismic transducers in a single module makes it a highly flexible and valuable component for protecting a wide variety of critical machinery, including steam turbines, gas turbines, compressors, and pumps, by providing both casing and shaft vibration measurements.