A CO detector based on electrochemical sensor which uses CO—7G fuel cell type electrochemical CO sensor is designed and working principle of CO electrochemical sensor and composition of circuit of detector are analyzed.The hardware circuit of detector is made up of signal conditioning circuit for electrochemical sensor

digital display circuit

data processing and control circuit based on MCU

4

20 mA analog output circuit

relay control circuit

and so on.MCU deals with collected datas by mean filtering algorithm

which improves sensitivity of system

reduces response time of detector and reduces false alarm rate.Experimental results prove that the error of this CO detector is less than 0.001 16 mg / L and the error is not more than 0.005 82 mg / L in one mont

h.This CO detector has the characteristics of high sensitivity

fast response

high measurement precision

good stability and has a high practical value.