HOW TO USE A MULTIMETER FOR APPLIANCE TROUBLESHOOTING & REPAIR
Learn How to Use a Multimeter
- What is a Multimeter?
- 2 Types of Multimeters
- What can Multimeters Measure?
- What is Voltage, Current, etc…?
- How to Measure Continuity, Ohms, Resistance, etc…?
- What are the Different Types of Multimeters?
- What is the Best One to Buy?
Why is the Multimeter Considered to be the Most Important Tool for an Appliance Technician?
2 Types of Multimeters – Analog & Digital
Analog Meters – although older than the commonly preferred digital multimeter…
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.
Analog multimeters can sometimes be difficult to read because they display data as a needle moving along a scale—this can be a benefit because the display of increased voltage (or resistance and so forth) is tangible, but can be hard for those unfamiliar with the scale.
Like their digital counterparts, analog multimeters can measure a range of different electrical outputs, such as voltage, current, and resistance—as done with digital multimeters, a function must be selected and a corresponding range must be set.
Digital Multimeters – are more modern and more accurate than Analog Multimeters.
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.