nHz is Nanohertz 1/1,000,000,000 Hz (Billionth)
µHz is Microhertz 1/1,000,000 Hz (Millionth)
mHZ is Millihertz 1/1,000 Hz (Thousandth)
Hz is Hertz 1 Hz (Base Unit, one per second)
kHz is Kilohertz 1,000 Hz (Thousand)
MHz is Megahertz 1,000,000 Hz (Million)
GHz is Gigahertz 1,000,000,000 Hz (Billion)
THz is Terahertz 1,000,000,000,000 Hz (Trillion)
I suppose there are probably more that I’m not aware of, but I hope this clears it up.
No, that absolutely does not resolve the confusion between meter (m) and milli (m)
Standing alone ‘m’ is metre.
With a decimal modifier ahead of it, ‘m’ is metre
Immediately before a symbol it is milli (one thousandth)
mm - the first m is before the metre symbol, it is the milli multiplier, the second m is after a multiplier, so it is the symbol for metre
mHz - the m is before the symbol Hz (for Hertz) so it is the milli multiplier
km - the m is after the K (kilo, thousand times) multiplier, so it is metre
You probably spell metre ‘meter’, but a meter is a whole different word in English
By convention, compound SI units (e.g. N•m) are separated by a space or multiplication dot and are not just smashed together. The lack of such a separator in the above example implies the “milli” prefix.
No one uses millihertz and neither meterhertz. If you want to do it correctly the first one would be acceptable for milli as scale. The second one would need to be written as m • Hz.
All metric unit prefixes are possible. Like femtohertz, picohertz, centihertz, decihertz, decahertz, hectohertz, petahertz, zettahertz. Not sure if they are used often.
