Thanks for the video. But I have a stupid question. What is the difference between the transducer which is used as a measurement device and the transducer which moves the valves stem?
Transducer just means a unit that changes one form of energy to another. Sensor and Transducer are the same thing, both terms are used to describe a sensor. The sensor/transducer changes one form of energy into another form (for example: a Thermocouple changes heat into millvolts) The transducer that moves the valve stem would be an I/P Transducer (Current to Pressure Transducer), basically a coil that takes the 4 to 20mA signal current and changes it into a 3 to 15psi signal to the valve body diaphragm.
Wow this is a very clearly explained video. I am studying mechanical engineering (trade) and couldn't understand control loops until I found this video. Thanks for your effort.
Pete, this video is uploaded in 2016, the same year I joined engineering college. Now I have graduated and going through my training in a factory for several manufacturing processes. I am finding your videos extremely helpful to revise and refine my knowledge and understanding. Thank you for your efforts. Thank you for this amazing channel!
Hello Pete, I've been doing this stuff for almost ten years now. Good work. Some may wonder how a motor could function as a final element. I've found that many motors used this way are controlled by a variable frequency drive .
Hi, I have a question. The process I work in has two backpressure controllers, PIC-A and PIC-C as well as pressure control valves. I cannot find a pressure transmitter in the operation book. Does that mean the PIC measures and control at the same time? or the pressure indicators are available on site but left out from the manual? can you please advise?
I have various videos on my channel. If you are on RU-vid in a browser (not in the App) you can search the channel for topics that interest you. Thanks for the comment. ru-vid.com
Hi, I am currently trying to identify control system components. For example, a measurement device e.g., a pressure transmitter or level transmitter; a controller e.g., DCS; and an actuator e.g., a valve. I am modeling pressure and level control systems using Fault Tree Analysis and want to establish the logic between the different components that make up the system. For example, if the DCS fails, we lose control of the process variable we are controlling (pressure for instance). I get confused about the terms sensor, transmitter, and transducer. Are they essentially the same thing? I am not sure if I have all the components listed above. Did I list all the components that have the potential to fail in a control system? would suggest other components to include? Best, Abdullah
Sensor = Transducer Every sensor creates a disgustingly small voltage or change in resistance, so a Transmitter is always needed to take the output of the Sensor/Transducer and send it out to the controller as a standardized signal (4-20mA or 0-10Vdc) Most loops in a control system are made up of Sensor & Transmitter / Controller / Actuator
The level control system I am modeling has the following loop: Level Indicator Transmitter (LIT), Level Indicator and Control (LIC) High or Low, if the level is High, a level indicator valve (LCV) will open to allow more flow; hence, reduce level. So the signal from the LIC to LCV is converted by a transducer? Note: the LCV is pneumatic which means an instrument air system is available to manipulate the valve.
Ok. So in that case, you have some Level Sensor with its associated Transmitter that sends the Level signal 4 to 20 mA back to the LIC (which is most likely a PLC), then the LIC sends a completely separate 4-20 mA signal to a I/P Current to Pressure Transducer (note that Transducer simply means a unit that changes one form of energy into another, so normally transducer is used as a name for the sensor... in this case they call the box beside the valve a transducer as well, because it changes a 4-20 mA signal into a 3-15 psi signal to the valve) www.emersonautomationexperts.com/2018/valves-actuators-regulators/what-are-valve-i-p-transducers/
@@DontLeaveMeLucile I am an electrician by trade, but I am mostly self taught. I put videos out to the world mostly to find out from the comments section whether my understanding of a topic is correct. If I am wrong, I get criticized from the audience... learn from my mistakes and incorporate the correct answer into my classes and further videos.
