The megohm meter (or megger) passes the 500, 750, 1000 volts to the wire that needs to be checked. According to ohms law R=V/I, the current in the returned voltage is measured and divided by the resistance (inside the meter). So when the current is high (i.e not properly insulated or leaking), the resistance value will drop otherwise resistance will be high.
Mega = million Megaohm = 1000000 Ohms
if it is ohm meter and not ohm per metre; divide by 1,000,000 to convert ohm to megaohm, then divide by 1000 further to convert metre into kilometre
A megger is used to test the resistance of high voltage cables, insulation and motor windings. The test employs a megohm meter.
Greater than 1 Megohm
To check any piece of electrical equipment for a short circuit a megohm meter will be used. The common name for this piece of equipment is a megger.
Strictly-speaking, this instrument is called a 'megohm meter', but is widely-known as a 'megger' which is the trade name of the company that manufactures the instrument.
A megohm is 1,000,000 ohms, so 2.2 megohms is 2,200,000 ohms, often abbreviated to 2.2M, or 2.2Mohm, or 2M2.
A "Megger" (which is short for "Megohm meter") is an instrument which generates a very high DC voltage so as to be able to test the quality of insulation which should have a very high resistance that can only be measured in megohms.
Connect a large but precisely known resistance in series with the galvanometer. For example, if you connect a 1-Megohm resistor in series with it, then the galvanometer will indicate 1 microampere of current when it's connected across a potential difference of 1 volt ... quite a sensitve voltmeter.
To test a motor, use a megger (megohm meter) to test the insulation of the internal motor windings. Select a voltage to apply to the motor using an output from the megger that is higher that the operating voltage that the motor operates on.
1,000,000 ohm
"Ohm" and its multiples is not a unit of current."Ampere" and its multiples is.The current through a 2.2-megohm resistance is(the voltage across the resistance)/(2,200,000) amperes .