Digital speech methane alarm

The utility model relates to a digital type stationary speech methane alarm which comprises an outer shell, a power supply, an electric bridge, an amplifier, a comparator, an alarm circuit, etc. The utility model is characterized in that the alarm circuit is composed of a single-chip speech circuit, a power amplification circuit and a special speech circuit stabilized power supply, the bridge circuit adopts a heating efficient type methane sensing element, and a methane concentration digital display is also fixedly arranged on an underground working face. The utility model can continuously monitor the methane concentration of the working surface. The speech sound, the light alarm, and the digit display the methane concentration. The trials of coal mines of a plurality of places show that the utility model has stable performance, convenient operation and convenient maintenance. The utility model is broadly suitable for the use of middle and small coal mines.