Measurement and Instrumentation - Types of Secondary Instruments
1 Answer
Secondary instruments, also known as secondary measuring instruments or secondary measuring devices, are devices used in measurement and instrumentation to indirectly measure various physical quantities. They rely on the measurement of a related quantity and use mathematical or physical relationships to determine the value of the desired quantity. Here are some types of secondary instruments:
Ammeters and Voltmeters (Direct-Reading Instruments): These are secondary instruments used to measure electric current (amperes) and voltage (volts), respectively. They are often calibrated to give direct readings of the measured quantity.
Wattmeters: Wattmeters are used to measure electrical power in a circuit. They combine the measurements of voltage and current to provide a direct reading of the power being consumed or delivered.
Energy Meters: Energy meters, such as kilowatt-hour meters, measure the total energy consumed or generated over time. They often incorporate wattmeters and integrate the power measurements to determine the total energy usage.
Frequency Meters: These instruments are used to measure the frequency of an alternating current (AC) signal. They can be based on various principles, such as resonance or counting cycles over a known time interval.
Power Factor Meters: Power factor meters determine the power factor of an AC circuit, which indicates the phase relationship between voltage and current. They help assess the efficiency of electrical systems.
Induction-Type Instruments: These instruments work on the principle of electromagnetic induction and are used to measure AC quantities, such as current and voltage. They include instruments like induction ammeters and voltmeters.
Dynamometers: Dynamometers are devices used to measure mechanical power, torque, and rotational speed. They are often used in applications like testing engines and machinery.
Pressure Transducers: Pressure transducers convert pressure (force per unit area) into an electrical signal. They are commonly used in industrial and automotive applications for measuring fluid pressures.
Temperature Sensors: Secondary temperature sensors, like resistance temperature detectors (RTDs) and thermocouples, measure temperature by sensing changes in electrical resistance or voltage across different temperatures.
Strain Gauges: Strain gauges are used to measure strain or deformation in materials, which can then be used to determine stress, load, or force applied to the material.
pH Meters: pH meters measure the acidity or alkalinity of a solution by measuring the potential difference between a pH-sensitive electrode and a reference electrode.
Flow Meters: Flow meters measure the rate of fluid flow in pipes or channels. Various types are available, including electromagnetic, ultrasonic, and turbine flow meters.
Gas Analyzers: Gas analyzers are used to measure the composition and concentration of gases in a sample. They find applications in environmental monitoring, industrial processes, and research.
These are just a few examples of secondary instruments used in measurement and instrumentation. Each type has its own principles of operation and applications, and they play a crucial role in accurately measuring and monitoring various physical quantities in diverse fields.
Ammeters and Voltmeters (Direct-Reading Instruments): These are secondary instruments used to measure electric current (amperes) and voltage (volts), respectively. They are often calibrated to give direct readings of the measured quantity.
Wattmeters: Wattmeters are used to measure electrical power in a circuit. They combine the measurements of voltage and current to provide a direct reading of the power being consumed or delivered.
Energy Meters: Energy meters, such as kilowatt-hour meters, measure the total energy consumed or generated over time. They often incorporate wattmeters and integrate the power measurements to determine the total energy usage.
Frequency Meters: These instruments are used to measure the frequency of an alternating current (AC) signal. They can be based on various principles, such as resonance or counting cycles over a known time interval.
Power Factor Meters: Power factor meters determine the power factor of an AC circuit, which indicates the phase relationship between voltage and current. They help assess the efficiency of electrical systems.
Induction-Type Instruments: These instruments work on the principle of electromagnetic induction and are used to measure AC quantities, such as current and voltage. They include instruments like induction ammeters and voltmeters.
Dynamometers: Dynamometers are devices used to measure mechanical power, torque, and rotational speed. They are often used in applications like testing engines and machinery.
Pressure Transducers: Pressure transducers convert pressure (force per unit area) into an electrical signal. They are commonly used in industrial and automotive applications for measuring fluid pressures.
Temperature Sensors: Secondary temperature sensors, like resistance temperature detectors (RTDs) and thermocouples, measure temperature by sensing changes in electrical resistance or voltage across different temperatures.
Strain Gauges: Strain gauges are used to measure strain or deformation in materials, which can then be used to determine stress, load, or force applied to the material.
pH Meters: pH meters measure the acidity or alkalinity of a solution by measuring the potential difference between a pH-sensitive electrode and a reference electrode.
Flow Meters: Flow meters measure the rate of fluid flow in pipes or channels. Various types are available, including electromagnetic, ultrasonic, and turbine flow meters.
Gas Analyzers: Gas analyzers are used to measure the composition and concentration of gases in a sample. They find applications in environmental monitoring, industrial processes, and research.
These are just a few examples of secondary instruments used in measurement and instrumentation. Each type has its own principles of operation and applications, and they play a crucial role in accurately measuring and monitoring various physical quantities in diverse fields.