Gas concentration signal acquisition of electrical modulation Non-dispersed Infrared (NDIR) sensors has advantages of
high measurement accuracy, adapting to wider concentration range, calibrating automatically and so on. Narrow-band
interference filter to some kind of gas detection is fixed on the sensor. Gas concentration can be showed by detecting
infrared ray's strength. Infrared source, gas room and infrared detector are set in one optical axis for better resolution of
gas infrared absorption signal. Some gas concentration detection system can be designed by using NDIR sensor. The
measurement accuracy of system is obviously improved by digital filtering, linear interpolation and temperature
compensation, etc. Through some literature materials researching, we find NDIR sensing and detection linearity is better,
and the detection error is higher, which can be applied in many kinds of gas monitoring instrument.
Intelligent distributed traffic signal light control system was designed based on technologies of infrared, CAN bus, single chip microprocessor (SCM), etc. The traffic flow signal is processed with the core of SCM AT89C51. At the same time, the SCM controls the CAN bus controller SJA1000/transceiver PCA82C250 to build a CAN bus communication system to transmit data. Moreover, up PC realizes to connect and communicate with SCM through USBCAN chip PDIUSBD12. The distributed traffic signal light control system with three control styles of Vehicle flux, remote and PC is designed. This paper introduces the system composition method and parts of hardware/software design in detail.