Features：    Use NDIR technology     Advanced, dual-wavelength measurement with no moving parts     Low-power consumption     Little calibration, high precision ,fast response     Analog output and RS232 output     Temperature inside could be for temperature compensate     Good immunity to other gases and humidity     Excellent long-term stability      Specifications：      Method：      Non Dispersive Infrared (NDIR), gold plated optics,   diffusion sampling      Performance：      CO2 measurement Range 0-2000ppm up to 0-5000ppm CO2      Resolution         10ppm      Max drift          ±2%FS      Accuracy           40ppm      Response time(T90)   <120s      Repeatability        <1%      Lifespan             >10 years      Operating environment：      Working temperature    0-50℃      Storage temperature    -20℃- +70℃      Temperature influent   <0.5%FS per℃      Working humility       0～95％RH no-condensing      Inputs and outputs：      Power supply           DC5V      Working current        90mA,max 150mA      Measuring output       linearity output      Output voltage         0-4VDC      Digital output         UART Data bit:8; Stop bit:1; Check  bit :null      Standard baud rate    9600bps      Dimensions            65*58*14.6mm(L*W*H)