Vogele Basic Training Hydraulics & Electrics

E.2.0 Units of measurement in electrics
E.2.7 Electrical resistance
Electrical resistance (symbol: R) is an electrical engineering term.
It is a measure of how much voltage is necessary for a specific current to flow through
an electrical conductor. The electrical resistance is generally temperature dependent.
The specific resistance of a conductor is equal to its resistance at a length of 1 m, a
cross-section of 1 mm² and a temperature of 20°C.
The symbol for electrical resistance is R.
This stems form the English word „resistance“ or „resistor“.
Units of measurement: MOhm (megaohm), kOhm (kiloohm), Ohm, mOhm (milliohm)
The ohm (Ω) (large Omega symbol) is the basic SI unit (SI = International System of
Units).
Every consumer, e.g. electric light bulb or heating rod, can be regarded as a resistor.
The system must be voltage-free to measure resistance!