What is instrumentation and control:

Instrumentation is a branch of engineering that we deals with the process variable and measurement of various parameters like:‐

Instrumentation refers to the process of using tools or devices (instruments) to measure, control, or monitor various physical, chemical, or biological variables in a system. This can include anything from measuring the temperature or pressure of a system, to monitoring the flow of a fluid, to analyzing the composition of a sample. Instrumentation is commonly used in many fields, including science, engineering, medicine, and manufacturing, to ensure that systems are functioning correctly, to troubleshoot problems, and to optimize performance. The instruments used in instrumentation can range from simple tools like thermometers and pressure gauges to complex systems like spectrometers and chromatographs.

1. Pressure.

2. Flow.

3. Temperature.

4. Level.

5. PH and Conductivity

Pressure:‐

Pressure measurement is the process of determining the force applied per unit area. It is commonly used to measure the pressure of gases and liquids in various industrial, scientific, and medical applications. There are several ways to measure pressure, but some of the most common methods include:

1. Mercury Barometer: This is a simple device that measures atmospheric pressure. It consists of a long tube filled with mercury that is inverted into a container of mercury. The pressure of the atmosphere is determined by the height of the column of mercury in the tube.

2 Bourdon Gauge: This is a mechanical device that measures pressure in a variety of applications, including steam boilers, air compressors, and refrigeration systems. It uses a curved tube that straightens under pressure, and the degree of straightening is proportional to the pressure.

3 Manometer: This is a device that measures pressure using a column of liquid. It is commonly used in laboratory settings to measure the pressure of gases.

4 Strain Gauge: This is a type of pressure sensor that measures the strain or deformation of a material caused by pressure. As pressure is applied, the material changes shape, and the strain gauge measures this change and converts it into an electrical signal.

5 Piezoelectric Sensor: This is a type of pressure sensor that measures the changes in electrical charge caused by pressure. It is commonly used in industrial and automotive applications. These are just a few of the many methods used to measure pressure. 

The selection of the appropriate method depends on the specific application and the level of accuracy required.

Flow:-

Flow measurement is the process of measuring the volume or rate of fluid (liquid or gas) passing through a given point in a system, typically in a pipe or conduit. It is an important measurement in various fields such as engineering, environmental monitoring, and process control.

There are various methods to measure flow, depending on the specific application and the characteristics of the fluid being measured. Some common methods for measuring flow include:

1. Differential pressure (DP) measurement: This method involves placing a constriction in the flow path and measuring the pressure drop across it using a differential pressure transmitter. The pressure drop is proportional to the flow rate.

2. Velocity measurement: This method involves measuring the velocity of the fluid using techniques such as ultrasonic flow meters, electromagnetic flow meters, or turbine flow meters. The flow rate is calculated by multiplying the velocity by the cross-sectional area of the pipe.

3. Mass flow measurement: This method involves measuring the mass flow rate of the fluid using techniques such as thermal mass flow meters, coriolis flow meters, or weigh feeders.

4. Open channel flow measurement: This method is used for measuring the flow rate in channels that are open to the atmosphere, such as rivers or canals. Techniques such as weirs or flumes are used to measure the water level and calculate the flow rate.

The choice of method depends on various factors such as the type of fluid, the flow rate, the pressure, and the accuracy required.

Temperature:-

Temperature measurement is the process of determining the amount of heat energy present in an object or a substance. Temperature is a measure of the average kinetic energy of the particles in a substance, and it is expressed in units of degrees Celsius (°C) or Fahrenheit (°F), or in the Kelvin (K) scale.

There are various ways to measure temperature, and the choice of method depends on the application, the accuracy required, and the range of temperatures to be measured. Some common methods of temperature measurement include:

1. Thermometers: A thermometer is a device that uses a liquid or a gas, such as mercury or alcohol, to measure temperature. The liquid or gas expands or contracts with changes in temperature, and the resulting change in volume is used to indicate the temperature.

2. Thermocouples: A thermocouple is a device that consists of two wires made of different metals that are joined together at one end. When this junction is heated or cooled, a voltage is produced that is proportional to the temperature difference between the two ends.

3. Resistance temperature detectors (RTDs): An RTD is a device that measures temperature by detecting changes in the electrical resistance of a metal wire. The resistance of the wire changes with temperature, and this change is used to determine the temperature.

4. Infrared thermometers: An infrared thermometer is a device that measures temperature by detecting the thermal radiation emitted by an object. These devices use a detector to convert the radiation into an electrical signal, which is then used to determine the temperature.

5. Thermistors: A thermistor is a device that measures temperature by detecting changes in the electrical resistance of a semiconductor material. The resistance of the material changes with temperature, and this change is used to determine the temperature.

The choice of temperature measurement method depends on the application, accuracy requirements, and the range of temperatures to be measured.

Level:-

Level measurement is the process of determining the height or volume of a substance within a container or process vessel. It is a critical aspect of many industrial processes, including chemical, pharmaceutical, food and beverage, and oil and gas.

There are various methods for measuring level, and the appropriate technique depends on factors such as the type of substance being measured, the container or vessel's size and shape, and the required accuracy and precision. Here are some common level measurement methods:

1. Sight glasses: This is a simple visual method of level measurement, whereby a transparent glass tube is mounted to the side of a tank, allowing the level to be observed directly.

2. Floats: A float is a device that floats on the substance being measured, and its position indicates the level of the substance. The float can be connected to a mechanical or electrical system to indicate the level.

3. Pressure measurement: Pressure sensors can be used to measure the weight of the substance above the sensor, which is then converted to level measurements. This method is commonly used for liquids, and it works by measuring the pressure exerted by the liquid on the bottom of the tank.

4. Ultrasonic measurement: Ultrasonic sensors send high-frequency sound waves into the tank, which bounce off the surface of the substance and are detected by the sensor. The time taken for the sound wave to be returned is used to calculate the level.

5. Capacitance measurement: This method uses a probe or sensor that generates an electrical field in the tank. The level of the substance can be determined by measuring the changes in capacitance caused by the presence of the substance.

6. Radar measurement: Radar sensors emit microwave signals that bounce off the surface of the substance and are detected by the sensor. The time taken for the signal to be returned is used to calculate the level.

Overall, the appropriate level measurement method depends on the substance being measured, the container's shape and size, and the required accuracy and precision.

PH:-

PH measurement is the measurement of the acidity or alkalinity of a solution, which is represented by its pH value. pH is a logarithmic scale that ranges from 0 to 14, where a pH of 7 is considered neutral, pH values below 7 are acidic, and pH values above 7 are alkaline (basic).

To measure pH, a pH meter or pH paper is typically used. A pH meter is a device that measures the electrical potential difference between a pH electrode (a glass bulb that contains a reference electrode and a pH-sensitive electrode) and a reference electrode. The pH meter displays the pH value based on the difference in potential between these two electrodes.

Conductivity:-

Electrical conductivity is the measure of a material's ability to conduct an electric current. It is a physical property that is essential in many fields, such as electronics, metallurgy, and materials science.

The unit of conductivity is Siemens per meter (S/m), but it is often expressed in terms of its inverse, which is resistivity (Ω⋅m).

There are various ways to measure conductivity depending on the type of material being tested and the required accuracy. Here are a few common methods:

1. Four-Point Probe Method: This method is used to measure the conductivity of thin films or small samples. Four probes are placed on the surface of the material, and a current is passed through two of the probes while the voltage is measured across the other two. The probe configuration helps to eliminate errors caused by contact resistance.

2. Conductivity Meters: These devices are used to measure the conductivity of liquids. A small amount of the sample is placed in a cell with two electrodes, and an alternating current is applied. The device measures the resulting voltage and calculates the conductivity.

3. Resistivity Meters: These devices measure the resistance of a material and calculate the conductivity. They are commonly used to measure the conductivity of metals and alloys.

4. Electrochemical Impedance Spectroscopy: This method is used to measure the conductivity of solutions or materials in contact with a liquid. The material is subjected to a range of frequencies of alternating current, and the impedance is measured. From the impedance measurements, the conductivity can be calculated.

Overall, the specific method used to measure conductivity will depend on the material being tested and the required level of accuracy.