Measuring Instruments and Errors

Instrumentation

• Measuring Instruments: Devices used to measure physical quantities, such as length, time, temperature, and pressure.
• Types of Instruments:
  • Analogue Instruments: Provide continuous signals, e.g., thermometers and ammeters.
  • Digital Instruments: Provide discrete numerical values, e.g., digital multimeters and oscilloscopes.
• Instrumental Errors:
  • Systematic Errors: Errors due to instrumental limitations, e.g., zero-point error.
  • Random Errors: Errors due to unpredictable fluctuations, e.g., thermal noise.

SI Units

• International System of Units: A standardized system of measurement units, adopted globally.
• Base Units:
  1. Meter (m): Unit of length.
  2. Kilogram (kg): Unit of mass.
  3. Second (s): Unit of time.
  4. Ampere (A): Unit of electric current.
  5. Kelvin (K): Unit of thermodynamic temperature.
  6. Mole (mol): Unit of amount of substance.
  7. Candela (cd): Unit of luminous intensity.
• Derived Units: Units derived from base units, e.g., velocity (m/s), force (N), and energy (J).
• Prefixes: Used to indicate multiples and fractions of units, e.g., kilo- (10^3), centi- (10^-2), and nano- (10^-9).

Instrumentation

• Measuring instruments are devices used to measure physical quantities such as length, time, temperature, and pressure.
• Analogue instruments provide continuous signals, examples include thermometers and ammeters.
• Digital instruments provide discrete numerical values, examples include digital multimeters and oscilloscopes.
• Systematic errors occur due to instrumental limitations, such as zero-point error.
• Random errors occur due to unpredictable fluctuations, such as thermal noise.

SI Units

• The International System of Units is a standardized system of measurement units adopted globally.
• The base unit of length is the meter (m).
• The base unit of mass is the kilogram (kg).
• The base unit of time is the second (s).
• The base unit of electric current is the ampere (A).
• The base unit of thermodynamic temperature is the kelvin (K).
• The base unit of amount of substance is the mole (mol).
• The base unit of luminous intensity is the candela (cd).
• Derived units are units derived from base units, examples include velocity (m/s), force (N), and energy (J).
• Prefixes are used to indicate multiples and fractions of units, examples include kilo- (10^3), centi- (10^-2), and nano- (10^-9).