There are seven base SI units.
The International System of Units (SI), the foundation of modern metrology, defines these seven base units, from which all other SI units are derived. These base units are:
- Meter (m): unit of length
- Kilogram (kg): unit of mass
- Second (s): unit of time
- Ampere (A): unit of electric current
- Kelvin (K): unit of thermodynamic temperature
- Mole (mol): unit of amount of substance
- Candela (cd): unit of luminous intensity
While the Tektronix article mentions 28 units, it's referencing the seven base units along with derived and other related units in the SI system. The core number of base units that define the SI system remains at seven.
