'Strength' is not a common thing to measure or talk about in physics, so I think you mean something else. Possibly force, which is measured in Newtons (N)
But to answer the question: The only case I know where the term is used is in material science, and material selection in design. It denotes the maximum amount of force per area of material that the material can handle, for instance before it stretches permanently or breaks. There are two main 'strenghts', namely the yield strength and the ultimate strength, and both are denoted by Pascals (or usually Mega Pascals, MPa). Pascal is nothing more than Force per Area, for which the SI units are Newton and Metre respectively(1Pa=1N/m²).
The scale used to measure the strength of an earthquake is called the Richter scale
the unit of measure used to categorize the strength of an earthquake.
The Richter magnitude scale is used to measure the strength of an earthquake.
Decibel (dB) is the unit used to measure the intensity of sound. This unit is also used to measure signal strength and amplification values in some scenarios.
A Gauss Meter, or magnetometer, is an electronic device that is used to measure the strength of magnetic fields. Gauss Meters are commonly used to measure the strength of magnets and magnetic effects in electronics. They can also be used as metal detectors.
there is a device called a hydrometer that measures humidity. theres a unit to measure heat called a calorie. those are two to measure it!
decibel
A Newton.
Richter scales are used to measure the magnitude of an earthquake. There is no specific unit used for earthquakes. I hope this helps. =)
SI unit kilogram is used to measure mass. It is abbreviated as kg.
A unit square.
It's called volume I think.