What is sensor sensitivity?

Sensor sensitivity is the ratio of electrical output to mechanical input. For accelerometers, it's typically expressed in mV/g (e.g., 100 mV/g). For velocity sensors, mV/(mm/s) or mV/(in/s). Higher sensitivity means larger output signal for the same vibration level.

How do I choose the right sensitivity?

Higher sensitivity (e.g., 500 mV/g) gives better signal-to-noise ratio for low-level vibration but limits the maximum measurable level. Lower sensitivity (e.g., 10 mV/g) is needed for high-g measurements. Match sensitivity to expected vibration levels and DAQ input range.

What is the dynamic range of a sensor?

Dynamic range is the ratio between the maximum measurable signal and the noise floor, usually expressed in dB. For IEPE sensors, max output is typically ±5V peak. Dynamic range = 20×log10(Vmax/Vnoise).

What is IEPE (ICP) sensor powering?

IEPE (Integrated Electronics Piezo-Electric) sensors require constant-current excitation (typically 2-20 mA) at 18-30V DC bias. The AC vibration signal rides on top of the DC bias. ICP is a trademark of PCB Piezotronics for IEPE technology.

Can I use a voltage divider to match sensor output to my DAQ?

Yes, but it reduces signal-to-noise ratio. Better approaches: use a sensor with appropriate sensitivity, adjust DAQ input range, or use a signal conditioner with programmable gain.

Free Engineering Tool — #017

Vibration Sensor Sensitivity Calculator

Calculate sensor output signal voltage from sensitivity and vibration level. Determine dynamic range and maximum measurable amplitude for IEPE accelerometers and velocity sensors.

AccelerometerVelocity SensormV/g · mV/(mm/s)

Results

Output Signal Voltage

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Max Measurable Level

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Output as % of Full Scale

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Dynamic Range

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Signal Level (dBV)

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Output Signal Voltage

Maximum Measurable Level

Common Sensor Types

Type	Typical Sensitivity	Range	Freq Range
General IEPE accel	100 mV/g	±50 g	0.5–10 kHz
Low-frequency accel	500–1000 mV/g	±5 g	0.1–1 kHz
Shock accel	1–10 mV/g	±500–5000 g	1–20 kHz
Velocity sensor	4–20 mV/(mm/s)	0.1–100 mm/s	1–1 kHz

Example — Standard Accelerometer

Given: Sensitivity = 100 mV/g, Vibration = 5 g pk, Max output = 5 V pk

V_out = 100 × 5 / 1000 = 0.500 V peak

Max level = 5000 / 100 = 50 g peak

Output = 0.5 / 5 × 100 = 10% of full scale

⚠️ Note: Exceeding the maximum output voltage clips the signal, causing distortion. Always verify that expected vibration levels stay within sensor range.