QB2000F single-point wall-mounted oxygen alarm detector is a kind of fixed type detector that can be used continuously in operation environment to detect the density of combustion gas, oxygen, or poisonous gas. The alarm detector adopt natural spreading method to detect the density of the gas, and it use the imported electric chemical sensor (flammable gas is catalytic combustion type) which has excellent sensibility and receptivity; big liquid crystal screen displays the density of the leaked gas real time and if the density exceed the preset alarm point it will start the acoustic-optical alarm or the exhaust system; international standard signal of 4-20mA can be directly connected into the factory DCS system, RS485 digital signal is connected with factory’s principle computer; the device adopts embedded micro controlling technique, the Chinese menu is easy to operate and the function is complete and reliable. The performance of the whole device is among the best ones in China. Characteristics: 　　◆ the device adopts advanced 16 digit ultra-low power consumption embedded micro controller. 　　◆ 128*64 dot matrix ultra-large liquid-crystal display 　　◆ user can set the alarm point by themselves 　　◆ Chinese menu is easy to operate for domestic customers 　　◆ Displaying the time of fist alarm 　　◆ real-time clock 　　◆ modularized sensor can be changed 　　◆ the automatic correcting function can decrease the measuring error. 　　◆1000 pieces of alarm record can be stored automatically 　　◆ standby battery can work more than 100 hours in the condition that do not work (optional) 　　◆ standard signal of 4-20mA can be directly connected into the factory DCS system 　　◆ RS485 digital signal is connected with factory’s principle computer ◆ Detect scope:0-25%VOL ◆ Apply to such gas as: flammable gas, toxic gas, oxygen ◆ Error show: ≤± 3% F.S ◆ Affecting time: T90<30s ◆ Displaying Method:128*64 dot matrix ultra-large liquid-crystal display for data and system condition ◆ Alarm: wide-angle LED, 100dB buzzer increases the frequency with the increasing of the density, treble vibrating alarm ◆ Operation condition:-30℃ ~ + 50 ℃; Humidity< 95%RH without moisture condescension ◆ Defending class:IP66