Improved Design For Energy-saving By IAS5000 Micro Near Infrared Spectrometer

Near infrared spectroscopy(NIR)has been rapidly developed in recent years due to its celerity,non-destructive and pollution-free.It has been widely used in agriculture and animal husbandry,food,chemical,medical,pharmaceutical,tobacco and other fields.With the continuous development of science and technology,NIR spectrometers have gradually become miniaturized and portable.However,compared with foreign countries,the market of portable miniature NIR spectrometers in China developed relatively late,and most of them have problems such as short battery life and high energy consumption.Therefore,the study on reducing consumption of portable miniature NIR spectrometers has far-reaching significance for promoting the development of NIR spectrometers.The present study aims to improve battery life and reduce energy consumption based on the IAS5000 micro-near-infrared spectrometer of China-IAS.The study consists of component selection,circuit design,system platform operation and functional design of the software.The design of the system contains three kinds of low power mode,i.e.sleep mode,stop mode and standby mode,which effectively reduces the overall energy consumption of the system and prolongs the battery life.The relevant performance tests and energy consumption tests had been carried out to verify the practical effect of the system.The main research contents are as follows:1.This paper analyzed the NIR spectroscopy technology theory and the working principle of the instrument,explained the rapid conversion between low-power modes and working mode,and analyzed the optimized design of the circuit in detail.An overall system solution was formulated to realize both hardware and software functions,and to reduce energy consumption as well.2.A reasonable operation scheme of normal operation including sleep mode,stop mode and standby mode of the near-infrared spectrometer was designed.The hardware system of NIR spectrometer was designed with STM32F407ZGT6 as the lower computer microcontroller,USB and bluetooth communication modes are adopted.Optimized power input and battery module to ensure stable output voltage and avoid unnecessary energy consumption;Bidirectional buck-boost switch converter was adopted to charge and discharge the battery.At the same time,the external devices are reselected and the working modes are configured to match the system consumption reduction.The temperature sensor module and adjustable light source module were designed to work together,and a reasonable operation mechanism was formed.3.NIR spectrometer software system was designed,including lower computer program and Android mobile client program.The lower computer program realized the reception and judgment of the return data of the upper computer,realized the functions of adjusting the light source intensity,deployed the working mode of the stepping motor and the speed regulating fan,read the temperature of the sensor and entered the corresponding working mode.Android client application controlled implements functions such as instrument self-test,scanning parameter setting,spectral scanning,spectral display and wake-up.4.The performance test and analysis were carried out for dark current,baseline drift,stability,light source stability,and absorbance reproducibility.The specific experimental results were as follows: The relative standard deviation of the dark current was between 0.0025~0.0067 AU,the relative standard deviation of the baseline was around 0.0003 AU,the relative standard deviation of the stability was less than 0.0005 AU,the light source was stable in the range of 2.0 s to 2.5 s,and the system was stable.The energy consumption of hardware had 10% of the consumption,compared to energy consumption before,the improvement average energy saved 0.0128 kW per hour,stop mode average energy saved 0.0137 kW per hour,system power consumption level dropped to amounts in standby mode.In normal working mode,the battery life had been extended by about 2.5 h,and even can be extended to 10 h in stop mode.The system designed to reduce consumption and improve its performance met the design requirements,the test verified that the energy consumption was significantly reduced and the battery life was significantly extended,which is of positive significance to promote miniaturization of the NIR spectroscopy instrument.