1. Sound pressure measurement

1.1 Sound level meters

The sound level meter is an instrument used to measure sound pressure. It is held in the hand, in front of the body.

Figure 1 shows a typical instrument with a length of around 20 centimetres. The cylindrical part on the left, with a diameter of 12 millimeters, contains a microphone that converts sound into electrical voltage. The microphone is placed at the end of a tube to reduce the influence of reflected sound waves on the instrument's body. The body of the instrument has an "aerodynamic" shape, which reduces wave reflection on the front part.

A block diagram of the electronics is shown in figure