Tag: process measurement
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Impeller Flowmeters: Features, Installation Considerations & Uses
Impeller flowmeters at times referred to as paddlewheel meters are one of the frequently utilized flowmeters for industrial flow measurement applications. Impeller flowmeters are cost effective compared to turbine meters and can be used in applications that are challenging to handle with other types of flow metering instruments. They are related to turbine meters in…
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How to Measure Pressure using a U-tube Manometer
There are three categories of pressure measurement, namely absolute pressure, gauge pressure and differential pressure. The absolute pressure is the differences between the pressure at a particular point in a fluid and the absolute zero of pressure, that is, a complete vacuum. When the pressure measuring device measures the difference between the unknown pressure and…
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Standard Process Signals for Industrial Instrumentation
Industrial measurement and control processes employ standard process signals that are used throughout all the industries. For instance, one of the most popular forms of signal transmission in modern industrial instrumentation systems is the 4-20 mA DC standard. The signal standards employed in industrial instrumentation are unique. Processes are referred to or measured as 0%…
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Basic Facts about 4-20 mA current loop in Process Instrumentation
The 4-20 mA current loop, like the one shown in the diagram below is a typical way of transmitting sensor information in most of industrial process monitoring applications. A sensor in this case is a device used to measure the physical parameters such as liquid flow rates, temperature, pressure, speed, and so on. The 4-20…
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How a Bubbler Device is used for Level Measurement
An often utilized technique of indirectly measuring a liquid level is to measure the hydrostatic pressure at the bottom of the container. The level can then be extrapolated from the pressure and the specific weight of the liquid. This is the principle that a bubbler device operation is based on. Pressure is commonly used as…
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Fiber Optic Temperature Sensors: Principle of Operation & Applications
As the name suggests these sensors employs fiber optics technology to function. A fiber optic sensor generally guides light to and from a measurement zone where the light is modulated by the measurand of interest and returned along the same or a different optical fiber to a detector at which the optical signal is interpreted.…
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Standards Used in Measurements & Their Classifications
For anyone performing a measurement using a particular instrument, it usually matters to know whether the instrument is calibrated or not. Calibration is required, along with precision, to enable accurate measurements to be made. Calibration means observing the instrument’s performance when measuring a standard of some kind. A standard is a physical representation of the…
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Electronic IC Temperature Sensors
Electronic IC temperature sensors are specialized integrated circuits that are used for sensing temperatures in the -55° C to +150°C range. Basic Principle of IC Temperature Sensors The working principle of IC temperature sensors is based on semiconductor physics. When the temperature of a p-n semiconductor junction changes, the mobility of the charge carriers in…
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What are Virtual Instruments?
Virtual instruments (VI) are instruments based on computer software whose controls and displays are presented on a computer screen and whose operation and settings are controlled by the keyboard and mouse. Instead of purchasing a number of expensive, dedicated, standalone instruments, users find it less costly to purchase a computer with a multichannel, analog-to-digital converter…
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What is Calibration of the Sensor?
Calibration of the sensor is the relationship between the physical measurement variable input and the signal variable output for that specific sensor. Typically, a sensor or an entire instrument system is calibrated by providing a known physical input to the system and recording the output. The data is plotted on a calibration curve such as…