Clamp meter Basics | How it works
This page covers Clamp meter basics.It mentions Clamp meter application note and Clamp meter manufacturers or Vendors.
The device clamp meter is basically an electrical tester which combines voltmeter functionality in clamp type current meter. As we have seen era of analog multimeter and digital multimeter similarly clamp meter was developed as analog type and now digital clamp meters are existing today. Moreover earlier clamp meters were used as single purpose test tool, but now they are used for multiple different measurements. Now clamp meters have come up with current transformer functionality built into it.
Let us understand how clamp meter works. The clamp meter measures large ac currents due to its transformer action. When we clamp the jaws of device around the conductor which is carrying the ac current, the current is coupled into the device. This is very similar to iron core of power transformer. The very small amount of current is taken inside due to number of turns ratio between primary and secondary windings.
If the turns ratio is about 1/1000 and if 1 amp of current is flowing which need to be measured would produce 0.001 amps or 1 mAmp of current at the clamp meter input.
Clamp meter measures any combination of alternating as well as direct current. This includes static dc,charging dc and normal ac. Usually Clamp meter measures DC current with the help of hall effect sensors.
Clamp meter Application Note
Clamp meter from FLIR systems has following silent features :
• Model No: EX840 CAT IV
• Built-in non-contact Infrared thermometer with laser pointer
• measurement of rms voltage and rms current
• Peak hold feature which captures inflow of currents & transients.
• It has multimeter functionality which includes measurement of ac/dc voltage, capacitance, resistance, frequency, diode as well as continuity test
• It supports 4000 count backlit display
• It has 1.7 inch jaw openings for support of conductors upto 750 MCM / 500 MCM (2 Nos.)
Clamp meter Manufacturers/Vendors
Following are popular clamp meter Manufacturers/vendors:
• Fluke India
• Extech Instruments
• Kyoritsu (http://www.kew-ltd.co.jp/)
• AEMC Instruments
• AideTek (http://www.aidetek.com/)