High Resolution Precision Milliohm Meter
Compact and precise, the Extech 380560 Milliohm Meter has 7 ranges and measures down to 0.1 milliohms using 4-wire Kelvin clip test leads. Measurements are displayed on the unit's large 0.8-inch, 1999-count LCD.
Automatic zero, 5V test voltage, and a built-in comparator for Hi/Lo/Go resistance testing or selection. Operates on 110VAC and comes complete with 4-wire cables with Kelvin clip connectors.
What is a MilliOhm?
The units of measure for resistances less than 1 Ohm (Ω) are Milli- (mΩ) and Micro-(μΩ)Ohms. One MilliOhm (1mΩ) is equal to one thousandth of an ohm (0.001). One MicroOhm (1μΩ) is equal to one millionth of an ohm (0.000001). For example, 0.5 ohms (one half an ohm) is equal to 500mΩ.
Why bother measuring resistances so low?
It may seem like too small a resistance to be of any consequence but many safety standards (UL, CSA, VDE, etc.) require that such resistances be measured during the manufacture of consumer products, hand tools, and many appliances. A good example is the testing of kitchen appliances.
Why are 4-wire connections required when making milliohm measurements?
Test leads always introduce a small amount of additional resistance into a measurement. This is acceptable in non-critical measurements such as megohm resistances. However, when measuring milliohms in a critical application, any additional resistance can render the measurement useless. This is why 4-wire (Kelvin) connections are imperative.