The five types of white cells and the approximate percentage they make up in the blood are: 1  Neutrophils (55% to 70%) 2  Band neutrophils (0% to 3%) 3  Lymphocytes (20% to 40%) 4  Monocytes (2% to 8%) 5  Eosinophils (1% to 4%) 6  Basophils (0.5% to 1%)
A sound level meter is an instrument that can measure sound level, commonly used in noise pollution studies for the quantification of different kinds of noise, especially for industrial, environmental and aircraft noise. common variant of the sound level meter is a noise dosemeter (dosimeter in American English). However, this is now formally known as a personal sound exposure meter (PSEM) and has its own International standard IEC 61252:1993.
On your sound level meter or noise meter you will often see references to Frequency Weightings such as âAâ, âCâ or âZâ. But what do these mean? Your ears are most sensitive to frequencies between about 500Hz and 6kHz and less sensitive to frequencies above and below these.