In order to detect Volatile Organic Compounds (VOC) quickly and accurately, a portable electronic nose system was developed which including signal acquisition module, valve control module, embedded modules. Three sensors were used to measure methane, ethanol and formaldehyde gas. We used a three-way valve to control two kinds of gas, in order to avoid the system noise the zero reference was subtracted with the gas being tested. The system could quickly detect the three kinds VOC. The system can play a positive role in the rapid assessment of pollution in industrial parks.

Microbial density is an important biochemical parameters of the training process. This article adopts the method of online measuring optical density of the reactor to obtain information on the growth of microorganisms, and flow photoelectric colorimetric instrument was developed based on this principles. Through MCU STM32F107VC output PWM to control peristaltic pump, to achieve the culture of continuous flow through the optical flow cuvette, using photocell to detect culture absorbed light intensity. The instrument can display detected parameters independently and adjust the control parameters, also can communicate with the PC by RS485. The instrument can achieve real-time monitoring of the growth of microorganisms in the reactor.