High-speed rail requires high-precision monitoring

Accurate quartz technology

The 2.1-mile long, gently curving viaduct stretches over a series of lakes and waterways. The bridge was built in an area of diverse landscapes including parks, open green spaces and water reservoirs. The valley underneath represents an intensely frequented public area. As part of a high-speed rail line putting considerable strain on the structure, therefore, precision instrumentation and constant monitoring are required. To that end, the bridge operator decided to integrate high-performance, servo-balanced quartz accelerometers at defined measuring points in the deck segments and the noise barriers of the bridge.

“When our UK distribution partner Strainsense received the request to provide high-precision sensors based on quartz technology, they spoke to us,” remembers Renate Bay, Managing Director of ASC Sensors. “To meet the brief, our team immediately went about customizing our quartz-based accelerometers to provide effective help in the structure’s monitoring and sound barrier deflection. Last week, we delivered the first batch of sensors for the project.”

The ASC QBA series

What resulted was the ASC QBA series: uniaxial quartz accelerometers for highest precision in structural health monitoring. With upgraded electronic circuitry to utilize flexible power supply of 9-36 VDC and a 4-20 mA analog current output for reliable data transmission, ASC’s quartz accelerometers were adapted to fit an application-specific housing. The robust, reliable stainless-steel housing of protection class IP67 can be equipped with a customer-specific connecting cable.

ASC QBA series accelerometers are readily available in vertical-mounted, uniaxial VX, VY or VZ sensitive directions. They are based on proven, high-performance servo-balanced quartz sensing elements, featuring a measurement range of ±30 g. The accelerometers offer a resolution of better than 1 μg to detect even the smallest vibrations, as well as outstanding long-term stability of the scale factor (K1: 1200 ppm) and bias (K0: 1200 μg).

Like for most of its flexible range of customizable inertial sensors, ASC is able to adapt the ASC QBA series to include tailormade biaxial and triaxial accelerometers. Also feasible, on demand, are even smaller measuring ranges of up to ±1 g as well as an optional voltage output signal.

HS railway and far beyond

ASC QBA accelerometers have been developed to provide high accuracy and long-term stability in structural health monitoring applications all over the world. With a temperature operating range from -40°C to +70°C they can be leveraged from the arctic circles to the world’s deserts almost without exception.

Beyond bridge monitoring and civil engineering, they are of value in a wide range of further high-end performance and measurement applications including train vibration and tilt control, conveying systems, seismic detection, automotive testing or navigation systems in the aviation and aerospace industries.

“We’re proud to be supporting high-speed railway, a key step towards a sustainable future of mobility and transport”, Bay says. “In essence, our ASC QBAs are highly flexible, high-performance accelerometers covering a broad range of precision measurement needs. Like with this rail infrastructure operator, we’ll work with you to adapt our sensors to your specs and unique business needs.”