.DETECTS METHANE AND PROPANE GAS ! 2.SINGLE COLOR LED DISPLAY 5-LEVEL LEAK ALARM AND READY !3.BATTERY LOW INDICATION !4.AUTO-CALIBRATION WHILE POWERS ON !5.BUILT IN EARPHONE JACK !6.FEATURES MUTE FUNCTION !7.SEMI-ConDUCTOR SENSOR IS REPLACEABLE !一氧化碳检测仪AZ7201的参数： FEATURE Quick to pinpoint gas leaks.Auto power off preserves remaining battery life.DC/AC 2-way power system for operation .8 LED lights indicate 40ppm 80ppm 160ppm 320ppm and 640ppm for Propane ; 120ppm 240ppm 480ppm 960ppm and 1920ppm for Methane.When power is on READY LED is off . LED is on after warm up time ( < 60seconds).Response time less than 2 seconds.High sensitivity features an audio mute switch button to silence the unit.Pinpoint gas leak with a 18" flexible probe in hard-to-rech areas.Detect Natural gas or propane fired heating system or gas pipelines.SPECIFICATIonDetect range:Methane : 120ppm - 1920 ppmPropane : 40ppm - 640ppmBattery:4 pcs of AAOperating temperature range:-5~45℃Flexible probe length:18" (465mm )Auto power off timeout:about 10 minutesWarm-up time:< 60 secondsResponse time:< 2 secondsSensitivity:40ppmDimension:175 x 70 x 38mm(HxWxT)Indicator:Acoustic intermittent beep and visual LED.Standard packing includes::Meter stainless flexible probe batteriesinstruction manual.