Difference Between Analog and Digital Multimeter

Main Difference – Analog vs. Digital Multimeter

multimeter  is a device which is used to make measurements such as voltage, current and resistance of an electrical circuit. The main difference between analog and digital multimeter is that the analog multimeter consists of a continuous scale over which a deflecting needle indicates the value to be measured, whereas, in digital multimeters, a digital display directly shows the value.

What is an Analog Multimeter

An analog multimeter is shown below:

Difference Between Analog and Digital Multimeter - Analog Multimeter

Difference Between Analog and Digital Multimeter – Analog Multimeter

To take a reading, firstly, the type of measurement (voltage, current, or resistance and whether the current is alternating or direct) and the expected range needs to be selected from the large dial below. Then, the leads (shown docked on the right) are placed at the relevant points on the circuit.

Central to the functioning of the analog multimeter is the D’Arsonval galvanometer. This consists of a coil carrying a current attached to a rotatable drum. Two permanent magnets are placed on either side of the coil. As current flows through the coil, a magnetic field forms around it. This magnetic field interacts with the magnetic field of the permanent magnet, so whenever the current flowing through the coil changes, the drum rotates. A needle is attached to the drum, which moves along the reading scale. An analog multimeter primarily measures current. Measurements of voltage and resistance are first converted to a corresponding current, which is then indicated by the needle.

Difference Between Analog and Digital Multimeter - D'arsonval Galvanometer Diagram and Real

Difference Between Analog and Digital Multimeter – D’arsonval galvanometer diagram and a real galvanometer

What is a Digital Multimeter

A digital multimeter is essentially a voltmeter. In order to measure current and resistance, some internal circuitry is used to “convert” current and resistance values to corresponding voltage values. Then, using an analog to digital converter, the voltage is converted to a digital signal and a value is displayed using a display, which is typically a 7 segment display. The image below shows a digital multimeter:

Difference Between Analog and Digital Multimeter - A Digital Multimeter

Difference Between Analog and Digital Multimeter – A Digital Multimeter

In older digital multimeters, the type of measurement as well as the range needs to be selected manually. Most new digital multimeters have an auto ranging feature. However, users still have the ability to manually select the range (this is especially useful when measuring values that change by large amounts periodically).

Compared to an analog multimeter, digital multimeters need not be calibrated as often. In addition, the readings are more precise and there is no chance for parallax errors to occur when taking a reading. However, it is difficult to take an accurate reading when a digital multimeter is used to measure a value which is constantly fluctuating. The following video contains a comparison of the two types of multimeters and a discussion of their relative advantages:

 

Difference Between Analog and Digital Multimeter

Display

Analog multimeter uses a printed, continuous scale. A needle moves along the scale to indicate a reading.

Digital multimeter uses a digital display.

Operating Mechanism

Analog multimeter uses a galvanometer which primarily measures current.

Digital multimeter measures voltage using an analog to digital converter.

Sources of Error

Taking readings from an analog multimeter may produce parallax errors.

With a digital multimeterit is difficult to determine an accurate average value when the reading is fluctuating.

Calibration

Analog multimeters need to be calibrated often.

Digital multimeters may also require calibration. However, they do not need to be calibrated as often as analog ones.

Image Courtesy
“Analog Multimeter” by KENPEI (KENPEI’s photo) [], via
“Diagram of D’Arsonval/Weston type galvanometer.” by Fred the Oyster () [], via  (Modified)
“A moving coil galvanometer.” by Wellcome Library, London (Library reference: Museum No. 116/1957, Photo number: M0016397) [], via  (Modified)
“One of the most popular high end 4 1/2 digit multimeters, the Fluke 87-V” by Binarysequence (Own work) [], via

About the Author: Nipun


Related pages


how are sigma and pi bonds formedarea of a regular polygonfairy faerie differencedifference between diarrhea and dysentrywhat is protoplasm in biologydifference between anion and cationaerobic and anaerobic respiration differencesbath or bathewhat is a nucleiodhow to calculate total equity on a balance sheetequation for buffer capacitywhat is smooch meansweiner dogs factsdamped vibrationundamped oscillatorwhat are examples of eubacteriadefine a heterogeneous mixturewhat do you mean by cold blooded animalsdifference between ethics and moralsdifference between panther and cougarshort ton to metric tonnesardonically definelysosome compositionhow are frankenstein and the monster differenthow to calculate bank reconciliation statementmetric ton versus tonmodernism to postmodernismidioms and cliches exampleswhat is the difference between a footnote and an endnoteliteral and figurative examples sentencebicameral legislatureswhat colour does ammonia turn litmus paperhow to find total equity on balance sheetillicit and elicitsame vowel sounds different consonant soundsstructural similarities between dna and rnadiscreet or discretedifference between moral and ethicproverb and adageconduction and radiation similaritiesdistinguish between radial and bilateral symmetrysigma bond and pie bondancillary units meaninga concave lens always forms an image which isdefine polyploidywhat is the difference between ham and porkdifference between monocot and dicot stemswhat is fertilization in plants definitionxenogamyhow to identify a fake pokemon cardexamples of micronutrientspermeability symboldifference between patronizing and condescendingintermolecular definition chemistryatp and adp differencecitric acid and ascorbic acidunipolar and bipolar depressiondefinition of enculturation907.18474 kilogramswhat is the difference between awaiting and waitingdizygotic twins definitioninquiries vs enquiriessorbet sherbetexamples of phonetics and phonologywhat is the difference between a tia and a strokewhat is a tragicomedyhow to make homemade anhydrous ammoniawhat is the difference between ultrasound and infrasounddifference between oxygenic and anoxygenic photosynthesisdefine jealousy and envyisopropyl ethyl alcoholneurosis and psychosis differencewhat is the difference between normative and positive economicsdistinguish between monocots and dicotshuman autosomes