Unit a℧
Name attomho
Category Electrical Conductance
Details Attomho (a℧) is a unit of electrical conductance in the field of electromagnetism and electrical engineering. It is a derived unit based on the mho, the reciprocal of the ohm (℧ = 1/Ω), and it represents attosiemens (aS) in the International System of Units (SI).

An attomho (a℧) is equal to 10⁻¹⁸ mho or 10⁻¹⁸ siemens (S). The prefix "atto" denotes a very small quantity or 10⁻¹⁸. Consequently, attomho is a unit to measure extremely low values of electrical conductance, typically used in situations dealing with very poor conductive materials or extremely low electrical currents.