MEMS-Based Gas Meter Flow Sensors

Experts predict that gas meters are poised to undergo the same change as electricity meters for smarter, remote meter reading. In response, STMicroelectronics and Omron have collaborated to provide a complete solution for electronic gas meter flow sensors. The design uses an Omron transducer and a companion analog front-end chip developed by ST. The resulting flow sensor incorporates a MEMS (Micro-Electro-Mechanical Systems) micro-thermal sensor technology and is intrinsically compensated for both temperature and pressure variations. A built-in circuit compensates for the variation of multiple gas composition.

Mounted on a small PCB (Printed-Circuit-Board) measuring 7.2×8.6 cm, the gas-flow sensor provides high accuracy with very low power consumption. The unit also has built-in motor drivers for valve control and protection against temperature and vibration effects. The sensor board uses the STLM20 temperature sensor and the LIS332AR accelerometer as well as an ultra-low power STM8L152 microcontroller with 32 Kbytes of flash memory and an LCD display driver.

For more information on the electronic gas meter flow sensors, click here.

Highly Integrated MEMS-Based Motion Sensing

Motion sensing is at the heart of several new features in consumer products including cell phone, tablet PCs and games. InvenSense has been a major player in these applications but its newest product family makes motion sensing even easier to design and manufacturer. MPU-6000 product family integrates a 3-axis gyroscope and a 3-axis accelerometer on the same silicon die together with an onboard Digital Motion Processor (DMP). The DMP can process the complex 9-axis sensor fusion algorithms required for motion sensing. Offered in a 4x4x0.9 mm QFN package, the MPU-6000’s sensor fusion algorithms utilize an external magnetometer output through its master I2C bus to provide dead reckoning functionality.

For more information on InvenSense MPU-6000 product family, click here.

High Temperature Pressure Sensor Targets Gas Turbine Monitoring

Most pressure sensors are offered in plastic packages and operate in a maximum ambient temperature of 125°C or less. Monitoring the pressure of a gas turbine requires a totally different approach. IMI Sensors Series 176 pressure sensors use  a stainless steel housing and piezoelectric sensing technology to tolerate the extreme heat environment (+986°F, +530°C) generated by  gas turbines. As a result, the units can be mounted directly to the combustor. The sensors have sensitivities to 17 pC/psi (2.5 pC/kPa) and ranges from 20 psi (140 kPa) dynamic to 400 psi (2760 kPa) static.

For more information on the IMI Sensors Series 176 pressure sensor click here.

Three-dimensional Hall Encoders for Industrial Apps

Austriamicrosystems is developing a portfolio of 3D Hall products for automotive and industrial applications. The 3D HallinOne magnetic encoder family provides absolute and highest resolution angular or linear output data.

The AS540x series uses two “pixel-cells” in a differential mode to guarantee robustness against all possible external influences like stray magnetic fields.  In addition, the IC contains an EEPROM to provide maximum flexibility to system designers when programming and linearizing the IC.  The use of this approach extends  the absolute linear position measurement range to 40 mm.

For more information on austriamicrosystems  AS540x hall encoder family, click here.

MEMS Sensing in Airbag Systems

LVDT Position Sensors Target Elevators

In elevator applications, Macro Sensors Spring Loaded LVDT position sensors measure the spring deflection as a result of the load. The sensors’ springs compress as an elevator is loaded with passengers to ensure that both cars and building floors properly align for each floor. Depending upon the elevator manufacturer, sensors are mounted either under or above the elevator car. 

The hermetically-sealed s (IEC IP-68) sensors are designed and manufactured for rugged applications enabling them to survive heavy shocks as well as the effects of dirt, water, steam and other corrosive elements without effecting performance. They are offered in stroke ranges of ±0.050” to ±-2.0” (±1.25 mm to ±50 mm) in both AC and DC input/output configurations.

For more information on Macro Sensors Spring Loaded LVDT position sensors, click here.

15-mm3 Package Contains MEMS Vibration Analysis System

Analog Devices just simplified the lives of industrial equipment designers who are tasked with implementing a vibration analysis system. Building on their MEMS accelerometer expertise, ADI has introduced the ADIS16227 iSensor, a tri-axial, digital vibration monitor that combines its iMEMS sensor, data conversion and sensor processing technologies with data capture and a serial peripheral interface (SPI).

The vibration monitoring aspects are quite unique for a system housed in a 15--mm³ package. The unit boasts embedded frequency domain processing, 512-point real value Fast Fourier Transforms (FFT), and the ability to identify and classify individual sources of vibration, monitor their changes over time and react to programmable threshold levels. The system has configurable spectral alarm bands and windowing options that allow the analysis of the full frequency spectrum with the configuration of 6 bands, a warning threshold (Alarm1) and a fault threshold (Alarm2 ) for earlier and more accurate detection of problems.

For more information on Analog Devices’ ADIS16227 iSensor vibration monitor, click here.

An Update on MEMS Sensors

Kionix New Gyros Target Consumer Apps

With analysts’ expectations of a $1.04B market by 2014, it is no surprise that Kionix has applied its MEMS expertise to consumer gyroscopes. The company offers both digital and analog versions of its dual-axis KGY12 and tri-axis KGY13. The 16-bit digital outputs (I2C and SPI) have a measurement range of ±2048°/sec. Analog outputs are available in user-selectable ranges of ±256°/sec, ±512°/sec, ±1024°/sec and ±2048°/sec. Both gyros are offered in a 5x5x0.9mm 24-pin land grid array (LGA) package and have user-definable bandwidth and embedded temperature sensors.

Get more information on Kionix dual-axis KGY12 and tri-axis KGY13.

Oops! Accelerometer Targets Drop Tests and More

Meggitt Sensing Systems Endevco model 7287 piezoresistive accelerometer weighs less than one gram. However, the accelerometer is not a light-weight when it comes to testing applications. The sensor targets the measurement of long duration transient shocks found in product and packaging drop testing, shipping container shock testing, jack hammer testing and high-g destructive testing.

The microelectromechanical system (MEMS) sensing element has integral mechanical stops and adds minimal mass to the test structure. The accelerometer has a measurement range of 2,000 g, 200 mV full scale output and a high resonance frequency of more than 20,000 Hz.

For more information about the Endevco model 7287 accelerometer, click here.

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