In this article, HBM explores the working principles of data acquisition systems and how they compare to alternative measuring technologies.
Data acquisition is a broad term that can be applied to a wide range of application areas. In a technical context, a data acquisition system (DAQ) defines a device or array that performs a range of functions to convert a mechanical or electrical signal into a digitized entity. Typically, the data acquisition system is connected to one or more sensors delivering an analog signal before being amplified, digitized, and analyzed in an appropriate format.
While data acquisition systems are most commonly utilized in the analysis of physical phenomena such as pressure and temperature, they can also be connected directly to electronic signals to measure and analyze waveforms of current or voltage.
A data acquisition system is based on several key components. When measuring analog signals, the foremost component is the sensor used to acquire a mechanical value such as mechanical stress or vibration. Various transducers are employed to acquire analog signals of interest with no universal solution available for comprehensive monitoring of mechanical phenomena. The success of a data acquisition system subsequently hinges on its available sensor connections.
Compatibility with a wide range of sensor and transducer types enhances the flexibility of the data acquisition system and ensures that the broadest possible range of signals can be acquired, amplified, and sampled. Amplification is carried out by the data acquisition system itself, enhancing the output amplitude of comparatively small input signals delivered by the sensor.
To store and analyze the acquired signals, they must first be sampled and digitized. This is most often carried out in parallel for all sensors signals connected which ensures the highest possible signal fidelity, compared to more “entry level” serial (or multiplexed) analog to digital conversion. Parallel sampling can be carried out at a resolution of up to 24-bit, representing an estimated range of ~ 16 million discrete values.
What separates a data acquisition system from a standard amplifier or data logger, however, is the ability to locally store, display, and analyze input data. Incoming signals can be visualized in real-time which ensures that all amplification and digitization settings are correctly established. This provides ongoing process control capabilities that can be manually monitored or allowed to run autonomously.
Data acquisition systems are routinely used in test and measurement applications, representing a comprehensive solution for process control, equipment calibration, or diagnostics. These basic features are often sufficient but modern data acquisition systems offer a plethora of additional benefits to enhance the accuracy of results, improve process autonomy, and much more. These include input isolation; advanced sensor and TEDS support; on-line computations; stand-alone operation; and integrated analysis.
Reliable input isolation reduces background noise and interference from the data acquisition system itself, while also offering more robust protections for both equipment and users from dangerously high voltages.
Advanced sensor and TEDS support are beneficial for noise prevention and easier handling with distinct mechanical signals including temperature and mechanical stress. This is enhanced by on-line computation capabilities which provide information in real-time which is typically not present in raw data.
Finally, the analysis capabilities of a data acquisition system elevate it above all other conventional technologies used for test and measurement equipment. Yet this is utterly dependent on the accompanying software.
HBM specializes in the development and supply of data acquisition systems for test and measurement, and R&D applications. We offer several product families that were custom designed for specific requirements. These include:
- QuantumX (universal data acquisition system)
- Somat (ruggedized data acquisition)
- Genesis HighSpeed
If you need any more information about our data acquisition systems, please do not hesitate to contact us directly.