Multi Meter
Measuring parameters, Features and Measuring process.
1 - Multi Meter:
A multimeter is a measuring Instrument which is used for measuring voltage, resistance and milliammeter of circuit or any Equipment. It is called a another name as VOM meter. It is two types one is analog and other digital.The analog multimeter shows the measuring value on the display by moving pointer but the digital multimeter shows on display as numerical value.
2 - Types of Multimeter:
Analog Multimeter
Analog multimeter works on electromagnetic functions and measured value is displayed by moving pointer on printed value disk. Measuring value is very easy to the reading on the display.
Digital Multimeter
Digital multimeter works on electronics functions and measured value is displayed on numeric form or seven segment display.
3 - Types of Measuring Parameters:
Resistance:
1 Ω - to - 100K Ω
DC Voltage:
.25 - to - 250 DC Voltage
DC Current:
.25 - to - 2.5 m
AC Voltage:
10 - to - 750V
AC Mili Ampere:
1.5 µ- to - 150mA
4 - Precautions of using Multimeter:
- Fix the pointer properly on zero position with the help of adjuster.
- The item range should be selected properly and according range, the knob also should be selected.
- The value of range should be selected higher for ex. voltage range should be kept higher as 750 volt.
- For current measuring the meter should be connected in series.
- The presence of voltage in any circuit, the resistance should not be measured.
- Keep the hand or finger away during measuring high voltage.
5 - Measuring process:
Measuring DC voltage
- Set he knob according DCV range.
- Connect the black test pin into negative and red test pin into positive point.
- Read the value on display.
Measuring AC voltage
- Fix the range selector knob according AC Voltage range.
- Connect the black test pin and red test pin into phase and neutral point.
- Read the value on display.
Measuring DC Ampere
- Fix the range selector knob according DC current.
- Connect the black test pin into negative and red test pin into positive point.
- Read the value on display.
Measuring Resistance Ω
- Fix the range selector knob according DC current.
- Short the black and red test pin and adjust the pointer on zero position so that the value could be check accurate.
- Connect the black test pin into negative and red test pin into positive point.
- Read the value on display.
Measuring Transistor
- Fix the range selector knob as 1 Ω to 1K Ω.
- For NPN transistor: connect the black test pin to collector and red test pin to the emitter
- For PNP transistor: connect the red test pin to collector and black test pin to the emitter
- Observe the value of leakage in mA and µA. value.
6 - Applications of Multi Meter:
Multi meter are used for low voltage electrical circuit, DC circuit, electronic circuit, printed circuit board etc.