Data Acquisition Systems Types and Terms
Types of Data Acquisition Systems
- is the process in which electric signals from various devices are converted into a digital form that can be analyzed.
- are acquisition systems that store information from various devices.
- receive and analyze information.
- enables computers to recognize and process signals received from monitoring devices.
-
need a computer to operate. These devices are programmable and allow
the user to choose the different interval readings.
-
are stand-alone instruments that do not require computer operation and
print the measurements directly on a chart.
-
(http://www.pressure-transducers.net)
are used to measure and record the pressure of a particular environment.
-
are a specific kind of data logger that record temperature and sometimes
humidity. Many of these devices are highly compact and can monitor conditions
inside packages; they also monitor the temperatures of facilities that
require regulated environments.
-
are very small and remote-controlled, and scan data by lasers. These
models are the latest technology in data acquisition systems.
Data Aquisition System Terms
- The sum of all factors
of error in a data acquisition device.
- The false reading
of high-frequency signals as lower-frequency signals. These readings are
expected errors from the discrete calculations with sampling devices like
analog-to-digital (A/D) converters.
- An apparatus
that attenuates the content of signals outside the preferred bandwidth
and comes before the analog-to-digital converter (ADC) in instrumentation
designs, which, in theory, permits the frequencies only in the pass band
to be sampled with the ADC.
- A signal that has a
value somewhere between two extremes and can constantly change.
- The procedure of converting
analog signals into a digital value or signal that is then able to be
stored on a computer.
- Transmission of data between receiving and transmitting
mechanisms in the form of zeros and ones. For correct data interpretation,
the receiving data needs to start at the appropriate location of the sequence.
- Protocol of data transmission for flood warning systems.
(
http://www.calibratingservices.com)
- The process of adjusting a device to increase its accuracy.
- The required
voltage range as related to the datalogger ground into which both inputs
of a differential calculation must fall in order to make a differential
measurement.
- Receiving data
from an RTU, datalogger or field recording apparatus. This process is
done locally or remotely, depending on the data retrieval peripheral.
- An input channel configuration consisting of
two signal wires coupled with each input signal, one wire for input and
one for return signals. The measurement is the variation of voltage between
the wires.
-
Analog measurements that measure the voltage between two inputs. Differential
measurements are able to reject noise better than single-ended calculations,
and can purge errors from differences in ground potential between the
sensors and the datalogger.
- Input/output
ports that sense status, read SDM peripherals or SDI-12 sensors and maintain
external devices.
- The electrical
current or voltage used with
transducers.
-
The use of a peripheral device to change a sensor's signal so another
non-compatible device is able to read the signal. Signal conditioning
mechanisms can be simple or complex.
- The frequent or periodic displacement of a signal away
from its intended location.
- A temporary storage location for information that has yet
to be processed or has not yet been transmitted.
- The lowest vital number at which a measurement is determined.
- The pace of measurements.
- Procedure of calculating a signal's value at discrete
time points.
- Amount of times per second that an analog signal
is measured as A/D conversion occurs.
- A measure of the minimum amount of change in a signal
that an instrument can detect.
- A device that responds
to a physical stimulus and generates an electrical signal or alters an
electrical property, such as resistance. The stimuli can be things like
light, sound, heat, pressure and motion.
- System that correlates redundant data storage with
measurement regulation, typically for regulating a manufacturing process.
Water treatment plants generally use SCADA systems.
- A sensor that converts
energy into readable electrical signals, which dataloggers measure and
record. Examples of these include
thermocouples
and strain gauges.