One of the easiest ways to check for faulty devices and parts, is to use a multi-tester, sometimes called a multi-meter. Testing continuity by using the ohm setting will tell you if the connection through the device is complete or if it has opened and is no longer usable. For instance, if you place one of the test leads on one side of a fuse and the other lead on the other side of the fuse, you should show a short circuit or 0 ohms. If your meter shows infinite resistance, the fuse is bad and should be replaced.
The multitester, also known as the multimeter, seems to have been invented by Donald Macadie, a British Post Office engineer.
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The battery is used by the meter to apply a voltage across the resistance being measured and determine the current which determines the resistance. If there is no battery it can't supply the voltage and can't measure current, so no reading.
A VOM will never do it. A curve tracer Will check all the parameters. Actually that goes for any other component you want to test.
Call a qualified electrician.If you are wanting to test a power circuit (120/240) at your home, there is no way to teach you on-line all the electrical safety (NFPA 70E) that you would need to know to use a multi-tester safely!Electricity is DANGEROUS!!Call a qualified electrician.Read the instruction manual!Depends on what you're using it for, to read voltage supply SWITCH ON meter, set it to volts (600volts for testing on for 230/400v supply) (200v for anything below) place red lead to live and black lead to neutral, to check continuity set it to ohms....actually to be honest im not going to go much further with answer, because you shouldn't really be near electricity if you had to ask that question!!!!!!!!!!!!!As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOBSAFELY AND COMPETENTLYREFER THIS WORK TO QUALIFIED PROFESSIONALS.If you do this work yourself, always turn off the power at the breaker box/fuse panel BEFORE you attempt to do any work ANDalways use an electrician's test meter having metal-tipped probes (not a simple proximity voltage indicator)to insure the circuit is, in fact, de-energized.
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=12&f=G&l=50&co1=AND&d=PTXT&s1=multitester&OS=multitester&RS=multitester
The multitester, also known as the multimeter, seems to have been invented by Donald Macadie, a British Post Office engineer.
They are easier to read.
the multitester and its parts
The black probe is negative.
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by using multitester
Turn the dial to the omega symbol.
By using a Multitester.
To test a flashlight bulb with a multitester, first set the multitester to the resistance (ohms) setting. Then, touch the probes to the metal contacts at the base of the bulb; a reading near zero ohms indicates continuity and that the bulb is functional. If the display shows infinite resistance (OL), the filament is broken, and the bulb is burnt out. Always ensure the flashlight is turned off before testing.
Donald Macadie, post-office engineer, invented the first multimeter in the 1920's. The original multimeter could measure volts, amperes and ohms.
Go to highest scale on AC range