Measurement system
Image of an electric motor system block diagram...
Image of the block diagram for pressure measurement..
Image of the block diagram for speedometer.
A system can be defined as an arrangement of parts within some boundaries which work together to provide some form of output from a specified input/inputs. The boundary devices the system interacts with the environment by means of signals crossing the boundary from the environment to the system i.e. input and signal crossing the boundary from the system to the environment i.e. output.
A simple way to representing a system is
Block diagram
Electric motor
Input→□→Output
Instrumentation system: for instrumentation system for making measured and has an input of the true value of the variable being measured and an output of the measured value e.g. A thermometer may be used to give a numerical value for the temperature of a liquid.
Loaning Effect:
This numerical value may not actually be the true value of the variable, there may be errors due to limited accuracy in the scale calibration or reading errors due to the reading falling between two scale markings or perhaps error due to the insertion of a cold thermometer into a hot liquid, lowering the temperature of the liquid and so altering the temperature being measured.
Block diagram for different example instrument system.
1. Pressure measurement.
2. Speedometer.
3. Flow rate measurement.
Block diagram for pressure measurement.
Measured system
Pressure→□→Value for pressure
Block diagram for speedometer.
Measured system
Speedometer →□→Value for speed.
Block diagram for flow rate measurement.
Measured system
Flow rate →□→Value for flow rate.
Image of the block diagram for flow rate.
Constitutent Element of an Instrumentation System.
1. Sensor.
2. Signal processor.
3. Data presentation.
4. Transducer.
Sensor is the part that is in contact with what we want to measure, it taps the signal and enters the system, and the signal has a processor which gives value, and the data instrumentation foward it for futher presentation/processing.
The transducer e.g. microphone, it is lime a converter which takes in, process and give output.
Simple diagram for measuring system element.
True value → Sensor → Signal processor → Display/Records/Transmit.
Image of a measurement system element.
Accuracy and Precision
The below image explains accuracy and precision.
Image explaining accuracy and Precision.
Unit of measurement
(primary)
1. Mass (kg)
2. Length (m)
3. Time (s)
4. Current (A)
5. Temperature (K)
6. Amount of substance (Mol)
7. Luminous intensity (cd)
(Supplementary ones)
1. Plane angle (Rad)
2. Solid angle (Sr)
3. Radioactivity (Ci)
The national standard by international agreement and are maintained by national establishments e.g. the national physical laboratory in Great-Britain, the national brewery of standard in United state.
So far we've listed seven (7) primary standards and three (3) Supplementary standards.
Thanks for checking up...
Incase of any mistake in the write up, leave a comment... thanks...
✍oladapo odedeyi.
Follow on Instagram @oladapoodedeyi
Thanks.