Microhms

Microhms refers to a unit of electrical resistance. The prefix "micro-" signifies one millionth, meaning one microhm is equal to 1 x 10^-6 ohms. The ohm, symbolized by the Greek letter Omega (Ω), is the standard unit of electrical resistance in the International System of Units (SI). Resistance is a property of a material that opposes the flow of electric current.

In practical terms, microhm measurements are used for very low resistance values, typically encountered in applications where high current flows or where even minute resistances can cause significant power loss or voltage drops. Examples include measuring the resistance of thick copper conductors, contacts in high-power switches, busbars, or the windings of large motors and transformers. Specialized equipment, such as micro-ohmmeters or Kelvin bridges, is employed for accurate measurement of these very small resistances. The precision required in these measurements necessitates careful consideration of contact resistance and lead resistance, which can be as significant as the resistance being measured if not properly accounted for. Understanding and measuring in the microhm range is crucial for ensuring efficiency and reliability in many electrical engineering contexts.