EPE221: Measurements and Instrumentations
Assignment 1: Classification of Instruments
Student Name: Abdelrahman Abdulmajeed Farid Alamrawy
UNI-ID: 120210093
Section : FOE-MTE-Group1
To
Assoc. Prof. Abdelfattah Eladl
Measuring instruments can be classified based on various criteria, including the
type of measurement they perform, the physical principle on which they operate,
their accuracy and precision, and their application. Here are some common
classifications of measuring instruments:
1. Mechanical and Electronic Instruments:
-Mechanical instruments use mechanical principles, such as
a.
b.
leverage or gravity, to measure a quantity. Examples include
balances, spring scales, and rulers.as shown in figure (1)(a)
- Electronic instruments use electronic circuits to measure a
quantity, and examples include digital multimeters,
oscilloscopes, and thermometers. as shown in figure (1)(b)
2. Direct and Indirect Instruments:
-Direct instruments measure a quantity directly, such as a
ruler measuring length or a thermometer measuring
temperature.
-Indirect instruments measure a quantity indirectly, such as a
flow meter measuring the flow rate of a liquid by measuring
the pressure drop across a constriction in a pipe.
Figure (1) a. mechanical instrument
b. electronic instrument
3. Accuracy and Precision:
Accuracy refers to how close a measurement is to the true value, while precision
refers to how reproducible a measurement is. Measuring instruments with high
accuracy and precision are more reliable and desirable in many applications.
4.Non-Destructive and Destructive Instruments:
- Non-Destructive Instruments are designed to perform non-destructive testing,
such as ultrasound machines or X-ray machines, which are used to detect internal
defects in materials or structures without damaging them.
- Destructive Instruments are designed to perform destructive testing, where the
material or structure is damaged or deformed to measure its properties such as
hardness testers or impact testers
5. Smart or Non-Smart Instruments:
- Smart instruments are equipped with microprocessors, sensors, and
communication capabilities, allowing them to perform advanced functions and
transmit data to other devices. They can be programmed to perform automated
tasks, self-diagnose errors, and provide feedback on their performance. Smart
instruments are often used in industrial settings, where they can improve
efficiency, accuracy, and safety.
- Non-smart instruments do not have microprocessors or communication
capabilities. They provide a simple and straightforward way of measuring a
quantity, and their readings are typically displayed on a dial or a scale. Non-smart
instruments are still widely used in many applications, such as measuring weight,
length, and temperature, and they are often more affordable than smart
instruments.
6. The way the Instrument operate:
Contact Instruments: These instruments require physical contact with the
substance being measured. Examples include thermocouples, thermometers, and
pressure gauges.
Non-Contact Instruments: These instruments measure without requiring physical
contact with the substance being measured. Examples include infrared sensors,
ultrasonic sensors, and laser rangefinders.
Static Instruments: These instruments measure a fixed quantity or parameter.
Examples include temperature gauges and level gauges.
Dynamic Instruments: These instruments measure a changing quantity or
parameter. Examples include flow meters and oscillators.
Recording Instruments: These instruments record measurements over a period of
time. Examples include data loggers and chart recorders.
Relative Instruments: These instruments measure a value relative to a known
reference point. Examples include differential pressure gauges and relative
humidity meters.