Left: Enlarged sample with SGs, middle: Sample on test machine, right: QuantumX MX1615
Comparative tests at Chinese university highlight QuantumX capabilities
HBM has won orders for a 144 channel system comprising five QuantumX MX1615 and four MX1601B modules. The orders followed immediately the QuantumX data acquisition system had proved its worth in a series of comparative tests conducted for a Chinese School of Engineering at one of the country’s leading universities.
The requirement: Precise measurement of forces acting during earthquakes
The university required a DAQ system that would produce accurate measurements of the potential forces acting on a structure during earthquakes. HBM and another DAQ manufacturer were asked to undertake the tests based on pre-determined criteria. The aim was to use the DAQ system on a vibration bench to simulate earthquake waves. Various models of bridges and buildings would then be tested to check seismic performance and long time reliability.
The university identified three parameters on the DAQ’s strain input channels – background noise, EMC and long-term reliability – as being critical. A variety of concrete and metal materials were tested where the main measurements were strain, force, displacement and acceleration. Strain was the most important measurand in the tests.
Test conditions and results
Test conditions included bonding strain gauges to a metallic sample which was then tested with various loads applied to it. The lead cables were first wrapped around a large electric motor and connected to the DAQ system to stimulate interference.
HBM’s results underlined the high quality of its DAQ equipment with a maximum zero drift shown as under ±5με with no obvious noise. The MX1615 enhances measurement flexibility because each channel can be individually parameterized and every channel is equipped with 24-bit A/D converters. The MX1615 has a data rate of 19.2 kS/s and a maximum bandwidth of 3 kHz per channel covering a wide analysis range.
The MX1615 can be easily combined with other modules such as analog outputs, digital inputs/outputs, CAN bus or EtherCAT connections. Data transfer to a PC is simplified by the use of Ethernet TCP/IP.
The QuantumX MX1601B is a universal amplifier for standard signals with 16 individually configurable channels for active sensors. The amplifier offers sample rates up to 19.2 kS/s per channel and a bandwidth of up to 3 kHz.
By contrast the competing DAQ equipment could only be demonstrated by connecting with demo strain gauges instead of the strain gauges bonded on the sample piece of metal. This was because its completion resistor did not match the resistance of the strain gauges bonded on the sample metal piece. In addition the cables connecting the strain gauges and the data acquisition system were not wrapped around the motor. Nonetheless, the noise signal had an amplitude of 30~40 με.