Instrumentation

Industrial instrumentation is the group of devices used to measure, record variables of a process, evaluate and control them.

Instrumentation is used to measure, control and monitor all the elements of an industrial system. All this with great accuracy, in addition to automating such processes and ensuring the repeatability of measures and results.

In all processes, it is absolutely necessary to control and keep constant some magnitudes, such as pressure, flow, level, temperature, pH, conductivity, speed, humidity, etc. The measuring and control instruments allow the maintenance and regulation of these constants in more suitable conditions than those that the operator himself could perform. In short, the instrumentation is responsible for keeping the process running optimally through elements that serve to measure, convert, transmit, control or record the variables.

These devices are used in machines such as reactors, pumps, furnaces, presses, compressors and a wide variety of industrial facilities.

That is, instrumentation devices are the tools to quantify physical or chemical facts in units of measurement. Such as (amps, volts, m/s, degrees Celsius, m³, liters, newton or kilogram-force, pascal-second, etc.). In an appropriate way to detect them, visualize them, record them and, thus, use this information for the control of the industrial process.

What concepts do I need to understand to get introduced to instrumentation?

Sensor: We call a sensor a device that automatically measures a variable, such as temperature, pressure or even the rotational regime, among other things.

Transmitter: It is known as transmitter in the field of instrumentation and control to the signal conditioner assembly.

Transducer: It is the instrument or device capable of transforming the available energy in a given physical magnitude into another magnitude, They are used for example to go from magnitudes conditioned in pressure to current or voltage and modernly to digital variables for fieldbuses.

Range: It is the set of values between the limits (Upper and Lower) that is capable of measuring the instrument to which we refer.

Resolution: It is the smallest change in the process variable capable of producing a perceptible output in the instrument.

Error: It is defined as the difference between the measured value and the true value.

Accuracy: Ability of an instrument to give small error values.

Accuracy: The higher the accuracy, the less dispersion of the measurement values around the measured value.

Repeatability: Ability of an instrument to repeat the output when the measurement is reached on several occasions under exactly the same conditions.

Hysteresis: is the ability of an instrument to repeat the output when it reaches the measurement on consecutive occasions under the same general conditions but once with the measurement of the variable in one direction (for example, increasing) and in the next with the variable in the opposite direction (for example, decreasing).

Calibration: Calibration is the process of comparing the values obtained by a measuring instrument with the corresponding measurement of a reference (or standard) standard.

Sensitivity: It is the variation in the output of the instrument per unit of variation of the process variable (input), in short, it can be said that it is the gain of the instrument.

Zero error: Even if the value of the process variable is at the minimum of the range, where the output of the instrument must be the value associated with the zero of the range (in current for example 4mA), the instrument marks at its output a non-zero value.

Linearity: It expresses how constant the sensitivity of the sensor or measuring device is. A constant sensitivity (high linearity) facilitates the conversion of the read value to the measured value.

Stability:Ability to keep your transfer curve unchanged for long periods of time.

Active – passive transducer: A transducer that is passive when it is not fed from any source other than the same process it is measuring.
On the other hand, the asset is one that in general needs less energy from the process itself to be measured since it has an external source for its operation.

Desired inputs: are the inputs to the measurement system of the physical variables that we want to measure.

Interference: They are unwanted inputs that the instrument detects without the intention of doing so.

Modifying inputs and perturbations: These are those that cause variations in the desired inputs as well as in the interferences