Data Acquisition Systems and Instruments

Data acquisition systems and instruments collect, digitize and process multiple sensor or signal inputs for the purpose of monitoring, analyzing and/or controlling systems and processes.  Data acquisition systems and instruments are configured in a wide variety of instrumentation and modular systems. Applications include manufacturing testing of all types of technical products, safety, environmental, certification and research projects.  Important specifications to consider when searching for data acquisition systems and instruments include differential analog input channels, digital I/O channels, sampling frequency, resolution, accuracy, and datalogger or recorder.  Differential channels use the difference between two signals as an input; common mode is filtered out. In some data acquisition systems and instruments, differential inputs are combinations of two single-ended inputs; in this case, twice the number of differential channels would be available as single-ended inputs.  Digital or discrete channels are used for low-level on-off signals used in applications such as communication, user interface, or control.  Sampling frequency is the frequency of the analog signal sampling and conversion to a digital value.  Resolution refers to the degree of fineness of the digital word representing the analog value. A ten-bit number contains 2¹⁰, or 1024, increments. A 0-10V signal could therefore be resolved into approximately 0.01V increments. A 12-bit representation would be in 2¹² (4096) increments, or divisions of 0.0024V for the same signal. Each additional bit doubles the resolution, and one bit is required for the polarity (sign) of a number.  Accuracy depends on the signal conditioning linearity, hysteresis, temperature considerations, etc. It is represented here as percent full scale of measurement range.  A datalogger or recorder is a unit with instrument functionality with specific capability for data storage. May be for general purpose or application-specific data acquisition.

Common form factor for data acquisition systems and instruments include IC or board mount, circuit board, panel or chassis mount, modular bay or slot system, rack mount, DIN rail, and stand-alone.  Common signal inputs available for data acquisition systems and instruments include DC voltage, DC current, AC voltage, AC current, frequency, and charge.  Sensor inputs include accelerometer, thermocouple, thermistor, RTD, strain gauge or bridge, and LVDT or RVDT.  Specialized inputs include encoder, counter or tachometer, timer or clock, and relay or switch.  Transducers and excitation are also important to consider when searching for data acquisition systems and instruments.  Many products have integral sensors or transducers.  These sensors can have voltage or current excitation.  Common outputs for data acquisition products include voltage output, current output, frequency output, timer or counter output, relay output, and resistance or potentiometer output.

Considering the user interfaces available is important when searching for data acquisition systems and instruments.  User interfaces available include no display, front panel and display, touch screens, hand-held or remote programmers, and computer programmable.  Host connection choices include direct backplane interface, RS232, RS422, ST485, USB, IEEE 1394, GPIB, SCSI, TTL, parallel, Ethernet, modem, and radio or telemetry.  The transmission rate of data is important to consider.  Many products are web enabled for web addressing.  Common applications for data acquisition systems and instruments are web enabled for web addressing include general lab or industrial, environmental, vehicular, marine, aerospace or military, seismic or geotechnical, weather or meteorology, and medical or biomedical.  Additional specifications to consider when searching for data acquisition systems and instruments include application software, memory and storage, network specifications, analog-to-digital conversion type, filter specifications, amplifier specifications, and environmental parameters.

• Data Acquisition and Signal Conditioning
  Data acquisition is the digitizing and processing of multiple sensor or signal inputs for the purpose of monitoring, analyzing and/or controlling systems and processes. Signal conditioning includes...
  (read more)
• The ALMEMO® system: One Instrument for All Sensors
  Since the first ALMEMO® handheld instrument was introduced in 1993, we have continuously improved the fascinating ALMEMO® system with its infinite possibilities for sensor connection, data...
  (read more)
• Instrument-Grade Data Acquisition with Ethernet Brings Precision Measurement and Control to Networks
  Amid the turmoil of evolving instrument capabilities, PCs losing expansion slots, and challenges to tried-and-true software and operating systems, users of computerized data acquisition (DAQ) systems...
  (read more)

Pages: 1 - 3 of 575