The XM® 121 Low Frequency Dynamic Measurement modules are general-purpose monitors. They are designed for low-frequency applications such as cooling tower fans, hydro turbines, and other types of low-speed, rotating machinery. They are suited for monitoring shaft, casing, or pedestal vibration in rotating equipment.

Features

• Two channels connect common vibration sensors (e.g., eddy current probes, accelerometers) and any sensor that outputs a voltage signal
• One tachometer channel that accepts input from most speed measurement sensors and can measure speeds 1…1.2M RPM with pulse rates 1…50,000 events per revolution
• Signal processing provides synchronous or asynchronous measurements
• Signal processing provides two levels of integration and FFT processing with as many as 30 measured parameters
• Two isolated, 4…20 mA outputs
• Single on-board relay
• Four virtual relays or four additional relays (when connected to an XM® 441 Expansion Relay Module)