Prefixes are provided in scales that function around 7 units known as metric system (or SI) base units. As shown in Table 1, base units include the meter (mmeter (mAn S meter (signal strength meter) is an indicator often provided on communications receivers, such as amateur radio receivers or shortwave broadcast receivers. ... The term S unit can be used to refer to the amount of signal strength required to move an S meter indication from one marking to the next.
› wiki › S_meterS meter - Wikipedia), the kilogram (kg), the kelvin (K), the second (s), the ampere (A), the candela (cd), and the mole (mol).