piezo vibration sensor

Geotechnical structures often vibrate at very low frequencies—think 0.1 to a few hundred Hz—when subjected to settlement, traffic, or seismic activity. Our piezo vibration sensors use a shear-type ceramic element that inherently rejects thermal transients and base bending, which is critical at these low frequencies. The built-in electronics are AC-coupled with a carefully chosen time constant so you can measure down to 0.1 Hz without excessive phase shift. For even lower frequencies, we can supply charge-mode sensors and recommend separate charge amplifiers with long time constants.

Absolutely. We don’t lock you into a proprietary system. Voltage-output sensors have a standard IEPE (ICP) interface that nearly all data acquisition systems accept—just supply a constant-current source. For charge-mode sensors, you need a charge amplifier, and we can suggest compatible units. If you need a tailor-made connection to an existing logger, our factory can pre-wire the sensor with your specified connector and pinout.

Piezo ceramics exhibit a change in sensitivity with temperature, typically a few percent over a wide range. Our sensors are tested from -40°C to +120°C, and each unit ships with a calibration certificate showing sensitivity at room temperature. If your monitoring site sees extreme temperature swings, we can provide compensated electronics or a temperature correction curve. Note that the low-frequency response can also drift if the sensor’s internal time constant resistor is temperature-sensitive, so we use precision thin-film resistors in the critical path.

We often adapt housings for borehole installation, magnetic bases, or epoxy bonding. We can extend or shorten the mounting stud, add a side-exit cable, or change the connector to something more durable like a metal bayonet. If you need a sensor that fits inside a small diameter inclinometer casing, we can slim down the body diameter and use a remote charge amplifier. The lead time is usually shorter than you might expect because many modifications start from proven platform designs.

In continuous geotechnical monitoring, a well-built piezo sensor can operate for decades if the environment is within its ratings. The key vulnerability is moisture ingress around connectors or cable splices, so proper sealing is essential. We double-seal all housing joints and use welded connectors where possible. The piezoelectric crystal itself does not wear out; what can degrade is the internal preamplifier (in voltage-mode sensors) over many years of thermal cycling. For critical long-term installations, we recommend periodic calibration checks—we offer a refurbishment service if sensitivities drift.