Analog multimeter vs Digital multimeter
There are two types of multimeters viz. analog and digital based on their measurement and display method. Following sections describes Analog multimeter and Digital multimeter and also mention difference between them.
In Analog Multimeter continuous deflection of a pointer over a scale represents the value of quantity being measured. Insite analog multimeter there will be current measuring moving coil meter with appropriate internal resistors which will be brought into circuit based on range switch selection. It is used to measure AC and DC current as well as voltage. It is also used to measure resistance. Multimeters are available to measure capacitors and transistors.
The actual resistance of analog multimeter depends on range chosen as well as on sensitivity. Figure-1 depicts analog multimeter type.
A Digital Multimeter is a electronic multimeter with digital decimal display for example LCD display. The measurement is displayed by ADC (analog to digital converter). For measurement of less magnitude voltage, it is amplified before being displayed.
For varying voltage measurement a latch circuit is used to hold the current sample before the last sample is measured and displayed. following are few of the basic differences between both type of multimeters. Figure-2 depicts digital multimeter type.
Following are important differences between the analog and digital multimeter types:
• Input resistance of digital multimeter is constant for all the ranges to be measured unlike analog multimeter.
• It measures with accuracy better than analog multimeter as analog multimeter is prone to errors due to wrong pointer based reading.
• The highest frequency of analog multimeter using rectifiers on AC range is about 2KHz. For digital electronic multimeter this range is higher than analog type.