ICP sensor system application technology – sensors, technology – HC net electric
Piezoelectric Accelerometer Sensor Vibration and shock Test Most widely used, but because of the pressure-sensitive piezoelectric sensor element with high impedance, requires a pre- Amplifiers The sensor's high impedance output signal is converted to low impedance signals. External pre-amplifier can be divided into two kinds of voltage amplifier and charge amplifier, voltage amplifier although the simple structure, linearity, and stability, but its sensitivity by Cable The impact of distributed capacitance, when the connection cable length changes, the voltage sensitivity can be changed. Although the sensitivity of the charge amplifier distribution by cable capacitance has little effect, but subject to vibration and bending of cable, cable core wire and insulator, insulator and metal shielding as between the relative Mobile Electrostatic charge generated by the friction will cause noise cable. These tests gave trouble.
ICP (Integrated Circuits Piezoelectric) sensor means built-in IC Piezoelectric sensors. And external pre-amplifier compared to the piezoelectric sensor, which can overcome these shortcomings. A typical ICP system commonly used constant current power supply, power supply cable at the same time as the signal output line, low impedance output signal. The whole system Package Including the ICP sensor, ordinary dual-core cable and an uninterrupted power supply, all the ICP system needs an uninterrupted power supply for the ICP sensor provides a constant current.
ICP sensor's high frequency response is usually limited by three factors: the natural frequency of sensor, built-in amplifier type, and transmission cables. ICP sensor's low frequency sound mainly consider two factors: First, the sensor discharge time constant; Another factor is the signal demodulator suitable coupling capacitor. If the signal output DC coupling mode, the low-frequency response depends only on the sensor discharge time constant, but will have zero drift of DC-coupling problems, most signals are suitable for AC coupling adjuster.
In order to improve low frequency performance acceleration sensors, there has been etched in silicon monolithic integrated accelerometer. The sensor has good low frequency performance, some of them can measure the static acceleration. AD's ADXL105 chip select Make A low frequency accelerometer test, its output impedance is less than 10W, there is a strong drive capability. Sensor frequency response the range 5Hz ~ 1kHz, 1kHz frequency response variation over the sensor's resonant frequency is about the 5kHz.
As the ADXL105 can measure both dynamic acceleration, it can measure the static acceleration (such as inertia, gravity), and therefore can be an absolute angle measurement. Sensors on the production point of view we also had to respond to test. ADXL105 also comes with a chip Temperature Sensor This will improve the temperature sensor in the test performance under field and solve the problem provided favorable conditions for temperature drift. ADXL105 chip temperature sensor output sensitivity 8mV/oC. Self-made sensor used in the field of environment temperature acceleration measurement was tested, test shows that the repeatability of measurement data better, which makes the use of intelligent sensor / transmitter system solution temperature drift and temperature field measurements possible.
Using ADXL105 chip temperature sensor with the measured temperature values, by surface fitting algorithm, which is two-dimensional regression analysis to solve the acceleration sensor of temperature and acceleration of cross-sensitivity. In considering the two factors of temperature and acceleration sensors that measure the value of U is the acceleration of output and temperature output Ut Ua dual function, namely, U = f (Ua, Ut), using two-dimensional quadratic surface fitting equation regression equation to express, you can write U = a0 + a 1Ua + a 2Ut + a 3Ua2 + a 4UaU1 + a 5Ut2 + e 1, a 0 ~ a 5 for the undetermined coefficients, e1 is the high order infinitesimal.
Identified within the range n-acceleration calibration points, m a temperature calibration points, then get n × m a calibration data, according to the n × m a calibration data to determine the regression equation coefficients. Quadratic surface fitting equation to determine the unknown coefficients in commonly used least square method to obtain the coefficient of variance of the minimum conditions are met.
By the quadratic surface fitting equation calculated U (Ua, Ut) value and the calibration error between the value of Uk, the variance can be expressed as Dk2 = [Uk – f (Ua, Ut)], a total of n × m were marked fixed, the mean square
For the smallest R value, according to multiple functions for extreme conditions, can make the following partial derivatives to zero, to its simultaneous equations, the experimental data points in the calibration, you can obtain the coefficient a0 ~ a 5, thus determine the quadratic surface fitting equation.
[Popular Keywords]: Sensor Technology Comment Large In Small
We are high quality suppliers, our products such as Multifunctional Drilling Rig , CFA Equipment for oversee buyer. To know more, please visits drilling rigs,drilling equipment.
Processing your request, Please wait....
