Capacitive Micro Accelerometer

 

Accelerometer, as the name suggests, are used to measure acceleration, and today’s science and technology requires inexpensive, fully functional, and large-scale processing and production of  accelerometer. In many fields, such as aerospace, machinery, and military industry, small and lightweight accelerometer are needed that can achieve many functions and are easy to test. The acceleration sensor integrated on the silicon chip has many advantages, micro acceleration sensor due to small and lightweight, conducive to mass production and other advantages, has been widely used in military, scientific measurement and other fields.

Micro accelerometer definition

Micro-electro mechanical systems (MEMS) are integrated miniature systems that combine electronic, mechanical, and other components, ranging in size from a few nanometers to micrometers, and are widely recognized in many fields. At present, micro acceleration sensor is one of the most widely used MEMS devices, which has the advantages of microfluidization, integration, intelligence, low cost, high performance and easy mass production. Applications range from smart phones, personal computers, the automotive industry and military defense. The micro-mechanical acceleration sensor based on MEMS technology has many advantages such as small size, light weight, fast start-up, low power consumption, easy integration, good reliability, strong anti-overload ability and low cost. According to the different types of sensitive signals, it can be divided into capacitive, piezoresistive and other micro acceleration sensors.

Structure and characteristics of capacitive micro-accelerometer

Capacitive micro acceleration sensor is the mainstream of MEMS acceleration sensor. Its basic structure is a capacitor composed of mass block and fixed electrode. When the mass block is displaced by acceleration, the capacitance pole area or distance is changed, and the acceleration is measured by measuring the capacitance. Capacitive micro accelerometers are the most common and mature products. The basic principle is to use the capacitor as a detection interface to detect the micro-displacement of the inertial mass due to the inertial force. The mass is supported by the elastic microbeam support on the substrate. One plate of the detection capacitor is generally disposed on the moving mass, and one plate is disposed on the fixed substrate. Figure 2 shows a typical sandwich-type flat capacitive micro accelerometer. Also, the capacitive micro accelerometer developed by AD uses a comb-tooth array capacitor as a detection interface. The capacitive micro accelerometer has high sensitivity and measurement accuracy, good stability, small temperature drift, low power consumption, and strong overload protection capability. It can realize feedback closed-loop control by using electrostatic force, which significantly improves the performance of the sensor.

For high-precision MEMS micro-accelerometers, performance stability is an important index of product quality. Under the same test conditions, such as temperature, humidity, etc., the repeatability of the same performance parameters of the device over a long period of time is called the stability of the device. Especially for capacitive MEMS micro accelerometers, due to changes in environmental factors or long-term storage, its zero drift and scale factors will change, thus reducing the accuracy of the device, resulting in long-term stability problems. Ericco introduced ER-MA-5,bias stability (Allan Curve)is 5μg, has the characteristics of small size, light weight, low energy consumption, can be widely used in vibration detection, attitude control, security alarm, consumer applications, motion recognition and state recording and other fields. The accelerometer is combined with a gyroscope and magnetometer to form an inertial measurement Unit (IMU).

At present, capacitive micro accelerometers have been gradually mature in the application of smart phone smart wearable medical and automotive industries. At the same time, with the continuous expansion of the market and technological upgrading, the application market of accelerometers continues to expand. Accelerometer application scenarios will have a broader space for development.

If you want to get more details about accelerometer,pls visit https://www.ericcointernational.com/accelerometer/

How to Correctly Select the Parameters of the Tilt Sensor

 

You need to choose your own tilt sensor according to your own needs.

Basic parameters of tilt sensor

1. Range

The range is the maximum range that can be measured by the sensor, which refers to the value of the difference between the upper and lower limits. Each sensor has its own measurement range, and when it is measured in this range, the output signal of the sensor has a certain accuracy. An acceleration sensor with a range of less than 1G is used as an inclination sensor, and a range of more than 1G is used as an acceleration sensor or vibration sensor. Because the larger the range, the less accurate. The biaxial tilt sensor ER-TS-4250VO can be selected in a range of +90°, while the uniaxial tilt sensor can be selected in a vertical direction of 360°.

2. Accuracy

In the process of testing and measurement, measurement errors are inevitable. There are two kinds of errors: systematic error and random error. The causes of system error, such as the inherent error of measurement principle and algorithm, inaccurate calibration, environmental temperature influence, material defects, etc., can be used to reflect the degree of influence of system error. The cause of random error is the gap of transmission components, aging of electronic components, etc. The precision can be used to reflect the influence of random error. Precision is a comprehensive index that reflects systematic error and random error, the higher the precision means the higher the accuracy and precision.

3. Zero offset

Zero drift means that when the input of the sensor is constant zero, the output value of the sensor will still change slightly to a certain extent. There are many reasons for zero drift, such as the change of the characteristics of the sensitive elements in the sensor with time, stress release, element aging, charge leakage, environmental temperature changes, etc. Among them, the zero drift caused by ambient temperature change is the most common phenomenon.

4. Input frequency

The frequency response characteristics determine the frequency range to be measured, and must allow the frequency range without losing the true measurement conditions, in fact, the sensor response will always have a certain delay. The higher the frequency response of the sensor, the wider the frequency range of the signal that can be measured, and the greater the interference. The lower the sensor frequency response, the narrower the frequency range of the signal that can be measured, and the lower the interference. In practical applications, a large number of measured signals are time changes, such as changes in current value, changes in object displacement, changes in acceleration, etc. This requires that the output of the sensor not only accurately reflect the size being measured, but also keep up with the speed of change being measured. In the frequency response range of the sensor, the amplitude of its output has a small change in the -constant range (maximum attenuation is 0.707). Therefore, when the input value is done sine

When changing, it is usually believed that the output value can correctly reflect the input value, but when the input value changes more frequently, the output value will produce significant attenuation, resulting in large measurement distortion.

5. Communication interface

RS232, TTL, RS485, RS232, CAN bus, voltage, current, SPI, IC, Profibus interface optional.If you want to learn more about tilt sensors or buy

Please contact me in the following ways:

Email: info@ericcointernational.com

Whatsapp: 13992884879

Application of Quartz Accelerometer in oil Drilling Field

 

With the sharp increase of energy consumption worldwide, oil and natural gas are still the first place in the world's energy consumption, and oil and gas will remain the irreplaceable main energy for economic and social development for a long time in the future. Therefore, the exploration and development of oil and gas resources has gradually entered deep, deep water, unconventional and other complex oil and gas, and complex oil and gas has become an important replacement energy in China and even the world.   

  In the process of drilling, drilling and completion fluid faces many challenges, such as insufficient temperature resistance of treatment agent and difficult control of rheological properties of drilling and completion fluid. These problems bring many difficulties to drilling work and put forward higher requirements for drilling equipment. Deep oil and gas drilling mainly has the following problems: bottom hole ultra-high temperature, high pressure, high stress environment.      

The ER-QA-03D is an accelerometer designed for applications in the oil and gas field with a measuring range of ±30g and zero bias stability of 50μg. The maximum operating temperature is 180℃and the impact resistance is 500-1000g 0.5ms. Aiming at the need of small installation space, the volume of ER-QA-03F is only Φ18.2×16mm and the page can ensure normal operation in high temperature environment. it's bias repeatability is 150-220μg and scale factor repeatability is 150-220 PPM.  

  Although there are many difficulties in the process of oil exploitation, with the progress of science and technology and the continuous improvement of quartz accelerometer technology, it can ensure that more resources are excavated in a safe operating environment.

If you want to know more about quartz accelerometers , please contact me through the following ways:

Web:https://www.ericcointernational.com/accelerometer/quartz-accelerometer

Email : info@ericcointernational.com

Whats app:13992884879

Do You Know What IMU is?

Gyroscopes and accelerometers are the main components of IMU, and their accuracy directly affects the accuracy of inertial system. In practical work, due to various inevitable interference factors, gyroscopes and accelerometers produce errors. From the initial alignment, its navigation error increases with time, especially the position error, which is the main disadvantage of inertial navigation system. Therefore, it is necessary to use external information to realize integrated navigation, so as to effectively reduce the problem of error accumulation with time. In order to improve reliability, more sensors can be equipped for each shaft. Generally speaking, IMU should be installed on the center of gravity of the measured object.

Generally, an IMU includes three single axis accelerometers and three single axis gyroscopes. The accelerometers detect the acceleration signals of the independent three axes of the object in the carrier coordinate system, while the gyroscopes detect the angular velocity signals of the carrier relative to the navigation coordinate system, measure the angular velocity and acceleration of the object in three-dimensional space, and calculate the attitude of the object based on this. It has very important application value in navigation.

IMU is mostly used in devices that need motion control, such as cars and robots. It is also used in occasions that require precise displacement estimation with attitude, such as inertial navigation equipment of submarines, aircraft, missiles and spacecraft.

🎀Summary

Using the three-axis geomagnetic decoupling and three-axis accelerometer, it is greatly affected by the acceleration of external forces. In the environment of motion / vibration, the output direction angle error is large. This field magnetic sensor has shortcomings. Its absolute reference is the magnetic line of force of the geomagnetic field. Geomagnetism is characterized by a wide range of use, but the intensity is low, about a few tenths of a Gauss, which is very easy to be disturbed by other magnets. If the instantaneous angle of the z-axis gyroscope is combined, It can make the system data more stable. The acceleration is measured in the direction of gravity. In the absence of external force acceleration, it can accurately output the roll/pitch two axis attitude angle, and this angle will not have cumulative error, which is accurate in a longer time scale. However, the disadvantage of the acceleration sensor in measuring the angle is that the acceleration sensor actually uses MEMS technology to detect the small deformation caused by the inertial force, and the inertial force is the same as gravity in essence, so the accelerometer will not distinguish the acceleration of gravity and the acceleration of external force. When the system changes speed in three-dimensional space, its output is incorrect.

The output angular velocity of the gyroscope is an instantaneous quantity, which cannot be directly used in attitude balance. The angular velocity and time integration are required to calculate the angle. The angle change obtained is added to the initial angle to obtain the target angle. The smaller the integration time DT is, the more accurate the output angle is. However, the principle of gyroscope determines that its measurement benchmark is itself, and there is no absolute reference outside the system. In addition, DT cannot be infinitely small, so the cumulative error of integration will increase rapidly with the passage of time, resulting in the output angle inconsistent with the actual, so the gyroscope can only work in a relatively short time scale.

Therefore, on the basis of no other reference, in order to obtain a more real attitude angle, we should use the weighting algorithm to develop strengths and circumvent weaknesses, combine the advantages of the two, abandon their respective shortcomings, and design an algorithm to increase the weight of the gyroscope in a short time scale, and increase the speed weight in a longer time scale, so that the system output angle is close to the real value.

🎀Working principle of IMU

IMU is a strapdown inertial navigation system. The system consists of three acceleration sensors and three angular velocity sensors (gyroscopes). The accelerometer is used to sense the acceleration component of the aircraft relative to the vertical line of the ground, and the velocity sensor is used to sense the angle information of the aircraft. This sub component is mainly composed of two a/d converters ad7716bs and 64K e/eprom memory X25650. The a/d converter uses the analog variables of each sensor of IMU, After being converted into digital information and calculated by CPU, the aircraft pitch angle, tilt angle and sideslip angle are finally output. The e/eprom memory mainly stores the linear curve diagram of each IMU sensor and the part number and serial number of each IMU sensor. When the part is just started, the image processing unit reads the linear curve parameters in e/eprom to provide initial information for subsequent angle calculation. Ericco provides FOG IMU and MEMS IMU solution, if you are interested, please feel free to contact us.

If you want to know more about IMU, please contact me through the following ways:

Web: https://www.ericcointernational.com/inertial-measurement-units

Email: info@ericcointernational.com

Whats app:13992884879

Tilt Sensor for 360° Dip Angle Measurement Under Coal Mine

Ericco 360D tilt sensor is designed by Ericco sensor for measuring tilt angle in coal mines. The tilt sensor can also be used in mining, steel, chemical industry and other fields that need to measure or control perpendicularity or tilt angle. Tilt sensors can be safely used in coal mines, oil fields and other environments with explosive gases.

360° Tilt Sensor (ER-TS-4250VO) Parameters:

Protection: intrinsically safe circuit design

Output interface: RS232,TTL, RS485,RS422, CAN, 0-5V, 0-10V, 4-20mA, 0-20mA optional, maximum output current＜45mA, accuracy class ≤0.1°, basic error＜+0.1%FS, protection level IP67

Measurement angle range: X.Y dual axis 0°~360° in any specified angle.

2. Material of tilt sensor:

The shell material of the tilt sensor is brass, fully sealed, and the leading wire is the mine explosion-proof flame-retardant wire, with high safety.

Ericco 360D Tilt sensor Features:

Easy installation, shock resistance, vibration resistance, high reliability, oil and corrosive gas resistance, explosion proof, cost-effective.

If you want to learn more about MEMS tilt sensors or buy

Please contact me in the following ways:

Email: info@ericcointernational.com

Whatsapp: 13992884879

What is Sensitivity and Measurement Range in Quartz Accelerometer?

 A quartz accelerometer is an instrument used to measure acceleration, commonly found in physics, engineering, and other related fields. When  design and select the quartz accelerometer,we need to consider the main specifications are: measurement range, sensitivity. The sensitivity of acceleration sensor is one of the most basic indicators of sensor. The sensitivity of the sensor directly affects the measurement of vibration signal. The measurement range of the acceleration value sensor refers to the maximum measurement value that the sensor can measure within a certain nonlinear error range. The nonlinear error of the universal piezoelectric acceleration sensor is mostly 1%. As a general principle,the higher the sensitivity, the smaller the measurement range,and the smaller the sensitivity, the larger the measurement range.

The sensitivity of the  quartz accelerometer

Sensitivity refers to the degree of response of a quartz accelerometer to changes in acceleration, usually expressed by changes in output voltage or current caused by changes in unit acceleration. The higher the sensitivity, the stronger the quartz accelerometer’s ability to detect small acceleration changes. Quartz accelerometer sensitivity – generally expressed in units such as WV/g or pC/g.

The capacitance of quartz flexible accelerometer is an important factor affecting its sensitivity. Generally,the larger the capacitor, the higher its vibration sensitivity, but the higher the sensitivity, the noise immunity will be reduced accordingly. Therefore, the capacitance size of the quartz flexible accelerometer needs to be selected reasonably.

The measuring range of the quartz  accelerometer

The measuring range of the quartz accelerometer is the maximum acceleration that can be measured under the specified performance index, which is measured and evaluated from both positive and negative directions. The level of acceleration supported by the acceleration sensor output signal specification is usually expressed as ±g, which is the maximum acceleration that the device can measure and accurately represent through its output. The ER-QA-03B designed for this purpose has measurement range of ±70g and bias repeatability of 10-30μg and scale factor repeatability of 15-50ppm. It is of great significance to improve the measuring range of quartz flexible accelerometer. First, with the rapid development of strapdown inertial navigation systems in recent years, the range of accelerometers that are required to be sensitive to has increased exponentially. If the magnitude of the linear acceleration exceeds the measurement range of the accelerometer, noise can be found in the output of the accelerometer, in which case the accelerometer does not properly reflect the input motion acceleration. Therefore, expanding the measuring range of quartz flexible accelerometer is an important strategic means to meet the needs of model development. In addition, the application field of quartz flexible accelerometer has gradually expanded, and many application fields have wider and wider measurement range requirements.

Application characteristics

The two basic indicators of sensitivity and measurement range have different requirements for different application scenarios. In the selection of quartz accelerometer, it is necessary to consider these indicators according to the actual needs to choose the most suitable quartz accelerometer. For example, in the field of aerospace, quartz accelerometers are required to have high sensitivity and a wide frequency response range in order to detect small changes in acceleration, and ER-QA-03A is designed for applications in this field with zero bias repeatability of 10-50μg and scale factor repeatability of 15-50 PPM. The second-order nonlinear repeatability is 10-30μg/g2.In the industrial production process, the linearity and temperature stability of the quartz accelerometer are required to ensure the accuracy of the measurement results.

Quartz  accelerometer has been widely used in various inertial navigation systems, and is one of the important measurement sensitive components in inertial navigation systems. With the development of inertial navigation systems, the requirements for inertial devices are becoming higher and higher. Sensitivity and measurement range as the most basic indicators of quartz accelerometer, but also the breakthrough point of the future development of quartz accelerometer technology.

If you want to know more about quartz accelerometers , please contact me through the following ways:

Web:https://www.ericcointernational.com/accelerometer/quartz-accelerometer

Email : info@ericcointernational.com

Whats app:13992884879

What are the Advantages of Tilt Sensor

 

The tilt sensor is a very accurate measuring tool for small angles. It can measure the inclination of the measured plane relative to the horizontal position, the parallelism and perpendicularity of the two components. It has become an indispensable and important measuring tool in bridge construction, railway laying, civil engineering, oil drilling, aviation and navigation, industrial automation, intelligent platform, mechanical processing and other fields.

1. The principle of tilt sensor

The working principle of the inclination sensor is based on microelectromechanical system (MEMS) technology and accelerometer principle. It is equipped with tiny accelerometers, and by using gravity, inertia and other mechanical principles, to detect the object’s tilt angle relative to the Earth’s horizontal plane.

When the object is at rest, the tilt sensor is subjected to gravity, which causes the accelerometer to align with the vertical direction of the Earth. When the object tilts, the direction of the accelerometer changes accordingly, resulting in an electrical output indicating the angle and direction of the object’s tilt.

2. Advantages of tilt sensor

The main benefits of tilt sensors include:

2.1 High Precision

The tilt sensor adopts MEMS technology, which has the characteristics of high precision, high stability and low noise, and can realize the high precision measurement and control of the tilt angle of the object. ER-TS-12200-Modbus is a high-precision wireless inclination sensor, its accuracy can reach 0.001°, using industrial MCU, three-proof PCB board, imported cables, wide temperature metal shell and other measures, its industrial design has extremely high measurement accuracy and anti-interference ability. It is suitable for remote real-time monitoring and analysis of industrial sites, dilapidated buildings, ancient buildings, civil engineering, tilt deformation of various towers and other needs.

2.2 Compact and Lightweight

The tilt sensor is small in size, light in weight, easy to install and carry, and is suitable for various occasions and environments. ER-TS-32600-Modbus its volume is 94*74*64mm, weight is only 460g, very easy to install and carry. Is an ultra-low power consumption, small volume, high-performance wireless inclination sensor, it uses lithium battery power, based on the Internet of Things technology Bluetooth and ZigBee(optional) wireless transmission technology, it meets the needs of users in industrial applications without power supply or real-time dynamic measurement of object attitude angle.

2.3 High Reliability

The tilt sensor has high vibration resistance, impact resistance, water and dust resistance, and can run stably in complex environment for a long time. For example, the ER-TS-3160VO, which has a seismic resistance higher than 20000g, is adopted IP67 protection grade, it has the characteristics of strong shock and vibration resistance, especially suitable for a variety of harsh industrial environments.

Summary: With the continuous development of technology, inclination sensors will have wider prospects and advantages.

1. High precision and stability: With the continuous improvement of measurement accuracy and stability requirements in various fields, the future development direction of inclination sensors will be to improve the accuracy and stability of induction components.

2. Multi-functional: the inclination sensor will gradually develop in the direction of multi-functional, such as integrating the functions of gyroscopes, magnetometers and other sensors to achieve the measurement of a variety of parameters.

3. Intelligent: inclination sensor will be combined with artificial intelligence, internet of things and other technologies to achieve intelligent perception and data processing, improve application efficiency and user experience.

4. Miniaturization: In order to meet the application needs of some special scenarios, the volume of the inclination sensor will gradually shrink and develop in the direction of miniaturization.

5. Wide application: With the continuous progress of inclination sensor technology and the expansion of application scenarios, its application in various fields will be more extensive, bringing more convenience to people’s life and work.