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.
Sound level meter. A sound level meter is used for acoustic (sound that travels through air) measurements. It is commonly a hand-held instrument with a microphone. The diaphrahm of the microphone responds to changes in air pressure caused by sound waves. That is why the instrument is sometimes referred to as a Sound Pressure Level (SPL) Meter. This movement of the diaphrahm, i.e. the sound pressure deviation (pascal Pa), is converted into an electrical signal (volts V).