Use a car seat with a harness for as long as possible, and keep it rear-facing for as long as possible (until your child reaches the manufacturer's height or weight limit). Keep your older child in a booster seat until at least 8 years of age and 57 inches tall. Have your child ride in a rear seat until age 13.
Flame atomic absorption spectroscopy instrument. Atomic absorption spectroscopy (AAS) is a spectroanalytical procedure for the quantitative determination of chemical elements using the absorption of optical radiation (light) by free atoms in the gaseous state.
1 Atomic absorption spectroscopy (AAS) : A technique used to identify the presence and concentration of substances by analysing the spectrum produced when a substance is vaporised and absorbs certain frequencies of light.2  AAS is used particularly for detecting the concentrations of metal ions in solutions. Atomic absorption spectroscopy (AAS) : A technique used to identify the presence and concentration of substances by analysing the spectrum produced when a substance is vaporised and absorbs certain frequencies of light.