It is defined by using caesium atomic clock (2 × 10-12). Coordinated Universal Time (CUT) is generated (at NMCC) by using the caesium atomic clock and comparing it to the time transmitted from GPS satellites (µs 3-2± (.
The second "s" (unit for measuring time).
It is defined as a basic unit by realizing two derived units volt and ohm by the equation: A = V / Ω
Ampere "A" (unit for measuring electric current)
It is defined through a group of electronic voltage reference cells on Zener Voltage Regulator, which is maintained at a high-constant temperature ±)µV/V 0.1).
The Volt "V" (unit for measuring Volt-measuring)
It is defined by using a group of standard resistors of 1 ohm maintained at a high-constant temperature with an estimated uncertainty of (0.06± microohms).
The Ohm "Ω" (unit for measuring electrical-resistance)