Multimeter
A multimeter or a multitester, also known as a VOM (Volt-Ohm-Milliammeter), is an electronic measuring instrument that combines several measurement functions in one unit. A typical multimeter can measure voltage, current, and resistance. Analog multimeters use a microammeter with a moving pointer to display readings. Digital multimeters (DMM, DVOM) have a numeric display, and may also show a graphical bar representing the measured value. Digital multimeters are now far more common due to their cost and precision, but analog multimeters are still preferable in some cases, for example when monitoring a rapidly varying value
Two Type of Multimeter available in Market
- Digital Multimeter –
- Analog Multimeter
Analog multimeter vs Digital multimeter
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.
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.
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.
There is two wire called probes , one is Red and second is black. In science red always be positive and black always be negative.
At the time , when you buy new multimeter be sure red probe insert in VΩ slot and black probe in COM slot (Mean Common ) | Third one 10A slot not use for mobile repairing.
