What is Instrumentation?


The first question that popped up in my mind and raised to our professor during the first day of my instrumentation classes was that what is Instrumentation and how is it being used in process control?  “Simple, these are instruments that we  use in order to measure, satisfy and complete a given sequence that will control the process required ” my professor replied. then I taught, Duh! Instrumentation is not that complicated and might be a boring subject but then when he goes along introducing the different kinds of instruments that are involve in the process, then I started to get interested and eventually loved the subject.

Then I started reading books to expand my knowledge on what instrumentation really does in process control. Instrumentation is actually the art of measuring the value of process parameters namely pressure, flow, level and temperature to name a few and supplying a signal that is proportional to the measured parameter. The output signals are standard signal and can then be processed by other equipment to provide indication, alarms or automatic control. There are a number of standard signals; however, those most common that we use are the 4-20 mA electronic signal and the 20-100 kPa pneumatic signal.

Sensors to measure speed, pressure, flow, level and temperature and valves to influence their behaviour and more complex instruments are what we are talking about here.  Below are the different types of instruments that are essential for all aspects of processes control. Further explanation, types and theory of each item will be explained in each separate article. just click on the types of instument to read more.

Temperature transducers


Pressure Transducers

Speed Transducers

Flow Meters

Force Sensors 

Position Sensors

Strain Guages

Level Sensors



  • Instrument is equipment used to help people for controlling something such as pressure ,temperature ,flow and so on
    For example when we take a bath using warm water we have to close or open cold and hot water to get suitable temperature for our body.
    In industrial process we can not do the control manually, that is why instrument is needed, such as transmitters, controller, control valve etc

    • Thank your for your clarification on this subject matter for the newbies mr. Djoko. i apologize for misinterpreting the comment below for I thought you were also a newbie.

  • Your statement is in detail and for explaining people who already knows instrument but still confuse with the definition
    My comment is for newcomer

  • Hi Mr Djoko..thank you for your comment. I understand your frustration in having a hard time understanding instrumentation. I also had the same sentiments when I was starting.

    Instrumentation exist everywhere a process is present. We have it at home, at the hospital and even in the cars..and even your body has some sort of instrumentation inside.Just think of a normal process we use at home. The heating/cooling of our room. What instrument will tell your AC that the room is already hot or cold.. We have a thermistor which is a different form of thermometer that we commonly use to check our temperature if we are sick.. The termistor will tell the computer of the AC or the cooling system that its already too cold depending on what tenperature you set. Thus the computer will then tell the motor to stop or close the valve in the case of other cooling systems. Now, the temperature in the room will vary from time to time depending on the ambient temperature outside the room or the number of people inside, thus the whole AC instrumentation will keep repeating the same process above to compensate to the temperature set in the computer.. You me read further about process controll in this link http://www.proconsol.co/2011/02/21/the-process-control-loop/ to fully understand a process control instrumentation..

    I hope i answered your query..

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