What are vibration sensors? How do they work, what types are there, and what are their uses?

What are vibration sensors?

Vibration sensors are transducers that detect mechanical vibrations and convert them into measurable electrical signals. They are primarily used to quantify three fundamental physical quantities associated with vibration.

How vibration sensors work（vibration sensing and vibration detection）

Here is a basic explanation of the structure and operating principle of Epson's vibration sensor.

Basic Structure

Crystal resonator: A crystal resonator is embedded within the vibration sensor. When subjected to vibrations, the oscillation frequency of this crystal resonator changes.
Crystal cantilever: The applied vibration is converted into a tensile or compressive force on the crystal resonator through the crystal cantilever and sensitivity adjustment weight.

Operating Principle

The oscillation frequency, which changes according to the magnitude of the vibration, is converted into physical quantities such as velocity, displacement, and acceleration, and output as digital values from the sensor.

Vibration sensors vs accelerometers

Vibration sensor are named after the phenomenon it is intended to detect, while accelerometers are named after the physical quantity they measure.
Vibration sensors can utilize displacement sensors or accelerometers to detect the magnitude (displacement, velocity, acceleration) and period (frequency) of vibrations.
Accelerometers can measure both periodic acceleration acting on an object and constant (DC) acceleration such as gravitational acceleration.
Epson's vibration sensors employs accelerometers and convert the measured acceleration into vibration velocity and displacement through internal calculations, before outputting the results.

Documents about features and functions of Epson's vibration sensors

Types of vibration sensors

Analog vibration sensors

Analog vibration sensors are devices that detect the vibration of objects and convert their magnitude into analog signals.
A distinctive feature of analog vibration sensors is that their output signal is a continuous voltage value. This voltage value is proportional to the magnitude of the vibration.
Analog vibration sensors offer advantages such as low cost, small size, and high-speed response. However, they also have drawbacks such as more susceptibility to noise and temperature drift.

Digital vibration sensors

Digital vibration sensors are devices that detect the vibration of objects and convert their magnitude into digital signals.
A distinctive feature of digital vibration sensors is that their output signal is an encoded value represented by a binary series of 0 or 1. This binary value is proportional to the magnitude of the vibration.
Digital vibration sensors offer advantages such as increased immunity to noise and reduced temperature drift. However, they are generally more expensive than analog vibration sensors and may not be suitable for high-speed response or wide frequency bandwidth measurements.

What are uses of vibration sensors?

Vibration sensors in seismic application（earthquake measurement）

Earthquake vibration sensors are primarily used for the following four purposes.

Early earthquake detection and warning

Detects P-waves (primary waves) of earthquakes to capture signs of an impending earthquake.
Estimates the magnitude and epicenter of an earthquake, contributing to rapid information dissemination and evacuation orders.
Contributes to the rapid issuance of tsunami warnings.

Measurement of earthquake magnitude and intensity

Estimates the epicentral distance from the time difference between the arrival of S-waves (secondary waves) and P-waves.
Measures earthquake acceleration and velocity to calculate earthquake magnitude and intensity.
Used in research to analyze earthquake focal mechanisms and fault movement.

Estimation of earthquake damage

• Measures earthquake ground motion to estimate building seismic performance and damage.
• Contributes to rapid assessment of post-earthquake damage and recovery activities.
• Utilized in risk assessment of secondary disasters such as liquefaction.

Earthquake research

• Used in research to elucidate earthquake generation mechanisms and propagation characteristics.
• Monitors the activity of active faults to contribute to earthquake prediction.
• Contributes to the development of technologies and disaster prevention measures to mitigate earthquake damage.

While vibration sensors can be used as earthquake vibration sensors, Epson recommends the use of accelerometers. This is because accelerometers are more suitable for the frequency range measured in earthquakes.

Documents about features and functions of Epson's vibration sensors

Vibration sensors in pump application (Pump vibration measurement)

Vibration sensors for pumps are used to detect pump abnormalities and contribute to predictive maintenance and fault prevention.
Specifically, they serve four main purposes.

Detection of abnormal vibrations

• Measures vibrations in pump bearings and casings to detect abnormal vibrations.
• Captures signs of pump failures such as cavitation, bearing wear, and bearing damage.
• By detecting abnormalities early, serious failures can be prevented, improving safety.

Efficient pump operation

• Monitors pump operating conditions by analyzing vibration conditions, promoting efficient operation.
• By suppressing excessive vibration, energy loss is reduced, leading to energy savings.
• Optimizing pump operating conditions can also extend the life of the pump.

Fault diagnosis

• By analyzing abnormal vibration patterns, the cause of pump failure can be identified.
• Specifically, failures such as bearing wear, bearing damage, and impeller damage can be diagnosed.
• Based on the results of the fault diagnosis, appropriate maintenance measures can be taken.

Predictive maintenance

• By collecting and analyzing pump vibration data, the deterioration of the pump can be predicted, allowing for maintenance measures to be taken before a failure occurs.
• Predictive maintenance prevents sudden failures and enables planned maintenance, leading to increased productivity and cost reduction.

Vibration sensors in ground applications（Vibration measurement of ground and structures）

Ground vibration sensors are used to detect ground vibrations and acquire various types of information. Specific applications are follows.

Earthquake detection and monitoring

• Detects P-waves (primary waves) of earthquakes to capture signs of an impending earthquake.
• Estimates the magnitude and epicenter of an earthquake, contributing to rapid information dissemination and evacuation orders.
• Contributes to the rapid issuance of tsunami warnings.

Ground stability assessment

• Evaluates ground stability by measuring ground vibrations.
• Helps assess the risk of ground disasters such as subsidence, liquefaction, and landslides.
• Used to confirm the safety of the ground in construction and civil engineering works.

Measurement of traffic vibrations

• Measures vibrations from roads and railways to evaluate the impact of traffic vibrations on the surrounding environment.
• Contributes to measures to prevent damage to buildings caused by vibrations and to reduce vibration noise.

Structural health monitoring

• Measures vibrations of structures such as bridges, dams, and buildings to diagnose their structural health.
• Early detection of structural deterioration and damage allows for appropriate repair and renovation, ensuring structural safety.

Other

• Groundwater flow measurement
• Geothermal exploration
• Exploration of underground resources
• Earthquake prediction research

While vibration sensors can be used for ground applications, Epson recommends using acceleration sensors. This is because acceleration sensors are more suitable for the frequency range of ground vibrations.

Vibration sensors in motors application（Motor vibration measurement）

Vibration sensors for motors are used to detect motor vibrations and serve four primary purposes.

Anomaly detection and predictive maintenance

• Detects abnormal wear and damage to motor components such as bearings, impellers, and casings, enabling predictive maintenance.
• Captures signs of failures like cavitation, shaft misalignment, bearing wear, bearing damage, and impeller damage.
• By detecting anomalies early, serious failures can be prevented, improving safety and maintaining productivity.

Efficient motor operation

• Monitors motor operating conditions by analyzing vibration conditions, promoting efficient operation.
• By suppressing excessive vibration, energy loss is reduced, leading to energy savings.
• Optimizing motor operating conditions can also extend the life of the motor.

Fault diagnosis

• By analyzing abnormal vibration patterns, the cause of motor failure can be identified. Specifically, failures such as bearing wear, bearing damage, and impeller damage can be diagnosed.
• Based on the results of the fault diagnosis, appropriate maintenance measures can be taken.

Quality control

• Measuring motor vibrations during the manufacturing process contributes to product quality control.
• Defective products can be detected and sorted early based on vibration levels.

Vibration sensors in industrial application（Machine vibration measurement）

Industrial vibration sensors are used to measure machine vibrations and acquire various types of information. Specific applications are follows.

Anomaly detection and predictive maintenance

• Detects abnormal wear and damage to machine components such as bearings, gears, and casings, enabling predictive maintenance.
• Captures signs of failures like cavitation, shaft misalignment, bearing wear, bearing damage, and gear wear.
• By detecting anomalies early, serious failures can be prevented, improving safety and maintaining productivity.

Machine condition monitoring

• Monitors machine operating conditions by analyzing vibration conditions, allowing for early detection of abnormalities.
• Detects abnormal vibration patterns to predict machine degradation and failures.
• Optimizes the timing of regular inspections and overhauls, reducing maintenance costs.

Quality control

• Measuring machine vibrations during the manufacturing process contributes to product quality control.
• Defective products can be detected and sorted early based on vibration levels.

Research and development

• By studying machine vibration characteristics, it contributes to improvements in machine design and the development of new technologies.
• By analyzing vibration data, the operating mechanisms of machines can be elucidated, leading to the development of more efficient and reliable machines.

Documents about features and functions of Epson's vibration sensors

Vibration sensors precautions

Precautions for installing vibration sensors

The location for installing vibration sensors varies depending on the measurement purpose and the objects being measured, but there are some common points to note.

Distance from the vibration source

• The vibration sensor must be installed at a distance that allows it to reliably capture the vibrations of the measurement target.
• If the distance is too far, the vibrations will weaken and accurate measurements cannot be made.
• Conversely, if it is installed too close, it will be susceptible to the influence of other vibrations.
• When determining the installation location, the vibration characteristics of the target object must be considered.

Surrounding environment

• The vibration sensor should not be installed in places where strong vibrations, shocks, high temperatures, high pressure, dust, or water are generated.
• The vibration sensor must be installed in a safe place where it cannot be touched or disturbed by people.
• Protective fences, etc. should be installed as necessary to prevent damage from falls or impacts.
• A location that is not affected by external conditions such as temperature, electricity, and magnetism should be chosen.

Stability of the installation surface

• The vibration sensor must be installed on a stable, flat, and hard surface.
• If the installation surface is unstable, the sensor will vibrate and cause incorrect measurements. If necessary, fix it using dedicated mounting brackets.

Power supply

• For vibration sensors that require a power supply, they must be installed in a location where the power cable can reach.
• Care must be taken to ensure that the power cable does not sag or become disconnected.
• For wireless models, choose a location where battery replacement is easy.

Data communication environment

• For vibration sensors with data communication functions, they must be installed in a location where radio waves can reach.
• If radio waves cannot reach the location, data communication will be interrupted, and data cannot be collected. If necessary, a repeater must be installed.

Epson as a vibration sensors manufacturer

Overview of Epson's vibration sensors

"Epson's vibration sensors are devices used to detect the vibrations of objects, measuring physical quantities such as displacement, velocity, and acceleration.
The basic structure consists of a quartz crystal resonator, a quartz cantilever, and a sensitivity adjustment weight. The oscillation frequency, which changes according to the magnitude of the vibration, is converted into a digital value representing the physical quantity of acceleration or velocity.
Epson's vibration sensors are equipped with three-axis detection elements with consistent characteristics, making them suitable for advanced vibration analysis."

Overview and lineup of Epson vibration sensors

Documents about features and functions of Epson's vibration sensors

Features of Epson's vibration sensors

Epson's vibration sensors are high-precision sensors that leverage quartz resonator technology. Key features are follows.

High precision

• Achieves high precision and stability thanks to Epson's unique quartz micromachining technology.
• Can detect even minute vibrations, making it suitable for precise measurements.

Compact and lightweight

• The adoption of a quartz resonator enables a compact and lightweight design.
• It can be installed in limited spaces, expanding its range of applications.

Low power consumption

• Low power consumption makes it suitable for battery-powered operation.
• Ideal for long-operating devices and applications requiring energy efficiency.

Wide detection range

• Can detect a wide frequency band from low to high frequencies.
• Capable of measuring various types of vibrations.

How to read and analyze vibration data from Epson vibration sensors using Arduino

There are three main steps to measuring vibration using Arduino and vibration sensors.

Hardware Preparation

• Arduino board
• Vibration sensor
• Jumper cables
• Breadboard (if necessary)

The necessary components and connection methods will vary depending on the vibration sensor being used. Here, we will use a general analog output accelerometer as an example.

1. Connect the Arduino board and the vibration sensor using jumper cables.
2. Connect the data output pin of the vibration sensor to an analog pin on the Arduino.
3. Connect the power and ground pins to the Arduino's power and ground pins, respectively.
4. If using a breadboard, connect as described above.

Software Preparation

• Arduino IDE
• Vibration sensor library (if necessary)

1. Download and install the Arduino IDE.
2. Download and install the library for the vibration sensor you are using. The installation method for the library will vary depending on the library, but generally it is done in one of the following ways:
   
   • Install from the Arduino IDE library manager.
   • Download the ZIP file and extract it to the Arduino IDE library folder.

Programming and Execution

1. Write the sample code suitable for the vibration sensor you are using and the measurement purpose to the Arduino IDE.
2. Upload the program to the Arduino board and run it.
3. Open the serial monitor and check the data from the vibration sensor.