Analog Multimeters

Electrical4u
03/27/2024

What Is Analog Multimeter

Multimeters as the name suggest the meters that we use to measure multiple quantities with the same instrument. The most basic multimeter measures voltage, current, and resistance. Since we use it for measuring current (A), voltage (V) and resistance (Ohm), we call it as AVO meter. We can categorise the multimeters into two groups, namely analog multimeter and digital multimeter. We will discuss here in this article about analog multimeter.

Analog multimeter was first of its type, but due to latest technological development after development of digital multimeters, nowadays it is of less use. However, despite such advancements, it is still essential, and we can’t neglect it. An analog multimeter is a PMMC meter.

It works based on the d’Arsonval galvanometer principle. It consists a needle to indicate the measured value on the scale. A coil moves in a magnetic field when current passes through it. The indicating needle is fastened to the coil. During the flow of current through the coil, a deflecting torque gets produced due to which the coil rotates at some angle, and the pointer moves over a graduated scale.

A pair of hairsprings is attached to the moving spindle to provide the controlling torque. In a multimeter, the galvanometer is a left- zero-type instrument, i.e. needle rests to the extreme left of the scale from where the scale begins with zero.
pmmc permanent magnet moving coil instrument
The meter acts as an ammeter with a low series resistance to measure direct current. For measuring high current, we connect a shunt resistor across the galvanometer so that the current through the galvanometer does not cross its maximum allowed value. Here, a significant portion of the current to be measured bypasses through the shunt. With that shunt resistance, an analog multimeter can measure even milli-ammeter or ammeter ranges of current.

For DC voltage measurement, the primary instrument becomes a DC voltage measuring apparatus or DC voltmeter.

By adding a multiplier resistance, an analog multimeter can measure the voltage from milli-volts to kilovolts, and this meter works as a millivoltmeter, a voltmeter or even as a kilo voltmeter.

By adding a battery and a resistance network, this instrument can work as an ohmmeter. We can change the range of the ohmmeter by connecting a switch to a suitable shunt resistance. By selecting different values of shunt resistance, we can obtain different scales of resistance measurement. Here below we are showing a basic block diagram of an analog multimeter.
basic block diagram of a multimeter

Here we are using two switches namely S1 and S2 to select the desired meter. We may use additional range-selector switches to choose particular range required in reading amperes, volts, and ohms. We use a rectifier to measure an AC voltage or current with the multimeter.

Advantages of Analog Multimeter

  • A sudden change in signal can detect by analog multimeter more swiftly than a digital multimeter.

  • All measurements are possible by using one meter only.

  • An increase or decrease in signal levels can be observed.

Disadvantages of Analog Multimeter

  • Analog meters are bulky in size.

  • They are bulky and costly.

  • The pointer movement is slow

  • Inaccurate due to the effect of earth magnetic field.

  • They are vulnerable to shock and vibration.

Statement: Respect the original, good articles worth sharing, if there is infringement please contact delete.

Electrical4u

Electrical4U is dedicated to the teaching and sharing of all things related to electrical and electronics engineering.

What is reactive power measurement?
What is reactive power measurement?
The power which exists in the circuit when the voltage and current are out of phase to each other, such type of power is known as the reactive power. The formula measures the reactive power in the circuitReactive Power Measurement & VarmetersReactive power measurement is critical as it indicates circuit power loss: low reactive power worsens load power factor, increasing system losses. Varmeters (volt-ampere reactive meters) measure reactive power and are categorized by circuit phases:Single
Edwiin
07/17/2025
What is a step voltage regulator?
What is a step voltage regulator?
Hey everyone, I'm Blue — an electrical engineer with over 20 years of experience, currently working at ABB. My career has mainly focused on circuit breaker design, transformer management, and providing power system solutions for various utility companies.Today, someone asked the question: "What is a step voltage regulator?" Let me explain it in simple but professional terms.So, a step voltage regulator is basically a device used in power distribution systems to keep the voltage stable. Think of
Master Electrician
07/11/2025
Classification of Electric Power Distribution Network Systems
Classification of Electric Power Distribution Network Systems
The typical electric power system network is categorized into three main components: generation, transmission, and distribution. Electric power is produced in power plants, which are often located far from load centers. As a result, transmission lines are employed to deliver power over long distances.To minimize transmission losses, high-voltage power is used in transmission lines, and the voltage is reduced at the load center. The distribution system then delivers this power to end-users.Types
Edwiin
06/05/2025
Why is the Ground Wire Always Positioned Above the Overhead Power Lines?
Why is the Ground Wire Always Positioned Above the Overhead Power Lines?
Ground Wire in Overhead Transmission LinesThe ground wire (also called earth wire or OPGW) installed above phase lines in overhead transmission lines acts as a key protective and safety component. It provides lightning protection, ground fault defense, and helps prevent electrical system disruptions.In overhead transmission lines, positioning the ground wire above phase lines serves specific safety and performance purposes. Referred to as a "shield wire" or "static wire," this configuration has
Edwiin
06/04/2025
Inquiry
Download
IEE-Business is dedicated to serving the personnel in the global power industry.
Join IEE-Business, not only can you discover power equipment and power knowledge, but also canhnd like - minded friends!