ABSTRACT
The standard international (SI) unit for the measurement of light wavelengths is the nanometre (nm).
1 nm = 10-9 m (one-thousand-millionth of a metre) 1 nm = 10 Å (Ångström units)
Light wavelengths are also sometimes given in micrometres (µm) 1 µm = 1000 nm = 10-6 m
Temperature
The standard international (SI) unit for temperature is the kelvin (K), and the degree Celsius (°C), both of which span equal temperature intervals. The kelvin is used mainly for thermodynamic work and represents an absolute temperature.
