Potentiometers and voltmeters both are measuring devices used to measure voltage. However, the major difference between Potentiometer and Voltmeter is that a potentiometer is used to measure the EMF of a Source(Voltage Source) whereas a voltmeter measures the potential difference between two points(Voltage) in a circuit. and there are many differences are described in the below chart.
What is a Potentiometer?
Potentiometer is a type of resistor device or three-terminal measuring device that is used to measure the unknown EMF or unknown Voltage of a Circuit with respect to the known EMF or known Voltage of a circuit. potentiometers are called pot or pot meters.
Potentiometer, commonly referred to as a “pot,” is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider. Potentiometers are used to adjust the resistance of a circuit, allowing users to control the amount of current flowing through the circuit. This, in turn, helps to control the output of a device, such as a speaker or motor.
the most common application of a potentiometer is to measure the EMF and internal resistance of a given cell.
What is a Voltmeter?
Voltmeter is an electrical measuring device used to measure the potential difference between two points. the voltmeter is also known as a voltage meter because it measures the voltage of the circuit. They are also used to measure the output voltage of a power supply or battery.
Voltmeters come in two types: analog and digital. Analog voltmeters use a moving pointer to indicate the voltage level, while digital voltmeters display the voltage level as a numerical value on a screen. Digital voltmeters are more accurate and precise than analog voltmeters.
When to Use Potentiometers vs. Voltmeters
Potentiometers and voltmeters are used in different scenarios based on their functions. Potentiometers are used to adjust the resistance of a circuit to control the output of a device, such as the volume of a speaker or the speed of a motor. They are also used in circuits where variable resistance is required, such as in a dimmer switch.
Voltmeters, on the other hand, are used to measure the voltage difference between two points in a circuit. They are used to troubleshoot circuits and to verify that the voltage across a load is within the expected range. Voltmeters are also used to measure the output voltage of a power supply or battery.
Difference between Potentiometer and Voltmeter:-
Parameter | Voltmeter | Potentiometer |
|---|---|---|
Function | An instrument used to measure voltage. | A three-terminal resistor with a sliding contact is used to measure potential difference, resistance, and current. |
Usage | Measures the potential difference between two points in a circuit. | Measures resistance and potential difference, and is used as a variable voltage divider. |
Connection | Always connected in parallel with the circuit under test. | Connected in series with the circuit under test. |
Measurement | Measures voltage directly in volts (V). | Measures voltage or resistance in ohms (Ω) or millivolts (mV). |
Internal Resistance | Designed to have a high internal resistance to avoid drawing significant current from the circuit. | Designed to have a low internal resistance to minimize voltage drop and power loss. |
Sensitivity | Generally more sensitive than potentiometers. | Generally less sensitive than voltmeters. |
Range | Typically have a fixed range. | May have a fixed or variable range. |
Accuracy | Generally more accurate than potentiometers. | Generally less accurate than voltmeters. |
Calibration | Usually factory calibrated and cannot be adjusted by the user. | May be adjusted by the user using a calibration screw or knob. |
Usage in Circuits | Used for measuring the voltage at a specific point in a circuit. | Used for measuring resistance and voltage drop across a portion of a circuit or as a variable voltage source. |
Applications | Used in electrical and electronic testing and troubleshooting. | Used in electrical and electronic testing and troubleshooting, as well as in audio and music equipment. |
Physical Design | Usually compact and handheld, with a digital or analog display. | Can be of various sizes and shapes, and may have a dial or knob for adjusting the resistance. |
Construction | Contains a galvanometer, resistor, and other components to measure voltage. | Contains a resistive element and a sliding contact to adjust resistance and measure voltage. |
Cost | Generally less expensive than potentiometers. | Generally more expensive than voltmeters. |
Power Consumption | It Consumes very little power from the circuit being tested. | May consume significant power from the circuit being tested. |
Input Impedance | Has a high input impedance to avoid loading the circuit being tested. | Has a variable input impedance, depending on the position of the sliding contact. |
Output Impedance | Usually has a low output impedance to drive other circuits. | Usually has a high output impedance, which may require buffering for some applications. |
Effects on Circuit | Has a negligible effect on the circuit being tested. | May affect the circuit being tested due to its resistance and impedance. |
Voltage Drop | Has a negligible voltage drop across its terminals. | May have a significant voltage drop across its terminals. |
Applications in Electronics | Used in measuring battery voltage, circuit voltage, and power supply voltage. | Used in audio equipment for volume control, tone control, and signal attenuation. |
Parameters | Measures voltage, current, and resistance. | Measures resistance and potential difference. |
Units of Measurement | Measures voltage in volts (V). | Measures voltage or resistance in ohms (Ω) or millivolts (mV). |
Conclusion:
In conclusion, the Difference between Potentiometer and Voltmeter are electrical measuring instruments, that serve different functions and are used in different applications. Potentiometers are primarily used to measure and regulate electrical potential, making them a popular choice for volume controls in audio equipment and other applications that require precise and variable voltage control.
On the other hand, voltmeters are utilized to measure the potential difference between two points in an electrical circuit, making them an essential tool for troubleshooting and circuit analysis. Understanding the differences between these two instruments is crucial to ensure that the right tool is selected for the job at hand.
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I am an electrical & automation engineer with extensive experience in Design, PLC programming, SCADA development, and IoT integration. I have a strong background in the industry, focusing on the Design & Development of Hardware, Software &Industry 4.0 technologies, and the integration of intelligent manufacturing systems.
I have a deep understanding of electrical principles and am proficient in various programming languages, including Ladder Logic, Structured Text, and Python. In addition, I have experience with various PLC, SCADA & IoT technologies and a track record of successful integration projects for various clients.