Operation Guide for Sound Level Meter

1. Overview

A digital sound level meter is an instrument that measures sound with a certain frequency and time weights, typically measured in decibels (Db (A)).

2. Application scope

Mainly used to measure the sound effect of alarm devices such as alarm broadcasting, hydraulic alarm bells, electric alarm bells, and buzzers.

3. Usage

3.1 Press the power switch (power on/reset button), and after 2 seconds, the displayed value on the screen is the A-weighted sound pressure level Lp.

3.2 If the sound level fluctuates significantly during measurement, press the "F/S" button to switch between F (fast) and S (slow).

When measuring, press the "LP/LMaX" button, and the display screen will show "HOLD", which means the maximum value is displayed.

4. Main matters

Measurement in windy environments requires the use of a hood to reduce the impact of wind noise.

5. Qualification criteria

5.1 In places with environmental noise greater than 60dB, the sound pressure level of the sound alarm should be 15dB higher than the background noise (such as fire broadcasting).

5.2 Use a sound level meter to measure that the sound pressure level at a distance of 3m from the hydraulic alarm bell is not less than 70dB after the alarm valve is activated.

The sound signal of the fire alarm should have a sound pressure level (A-weighted) of not less than 75dB at least 3m in one direction, and a sound pressure level (A-weighted) of not more than 120dB at 3m in any direction.