农业工程学报
農業工程學報
농업공정학보
2014年
16期
166-172
,共7页
杨运经%刘锴%习岗%高宇
楊運經%劉鍇%習崗%高宇
양운경%류개%습강%고우
发光%辐照%发光二极管%生物延迟发光%测量系统%设计%测试
髮光%輻照%髮光二極管%生物延遲髮光%測量繫統%設計%測試
발광%복조%발광이겁관%생물연지발광%측량계통%설계%측시
luminescence%irradiation%light emitting diodes%biological delayed luminescence%measurement system%design%testing
针对目前生物延迟发光检测系统利用外置激发光源存在的延迟误差和自然光叠加干扰导致的测量结果重复性不好和可靠性差的问题,设计了一种生物延迟发光辐照光源系统。该光源系统主要由恒温辐照室、三基色RGB-LED(light-emitting diode)矩阵辐照光源、电子快门隔离器及控制电路组成,并与BPCL系列微弱发光测量仪组装在一起使用。在51系列单片机的控制下,该辐照光源系统实现了光源频率和光强的多重选择以及辐照时间的程序化操作,实现了光照与检测之间在同一个暗室通道中通过电子快门的迅速切换,极大的降低了自然光的叠加干扰与延迟误差。背景噪声和稳定性试验测试结果表明,应用该系统使平均光子计数的噪声偏差不超过4.5 cps,5次重复测试的相对误差为0.7%,重复测试的延迟发光曲线具有良好的重合度。对萌发玉米延迟发光的测试结果表明,延迟发光曲线的拟合优度R2在0.99以上,应用该系统可以得到较为理想的结果。
針對目前生物延遲髮光檢測繫統利用外置激髮光源存在的延遲誤差和自然光疊加榦擾導緻的測量結果重複性不好和可靠性差的問題,設計瞭一種生物延遲髮光輻照光源繫統。該光源繫統主要由恆溫輻照室、三基色RGB-LED(light-emitting diode)矩陣輻照光源、電子快門隔離器及控製電路組成,併與BPCL繫列微弱髮光測量儀組裝在一起使用。在51繫列單片機的控製下,該輻照光源繫統實現瞭光源頻率和光彊的多重選擇以及輻照時間的程序化操作,實現瞭光照與檢測之間在同一箇暗室通道中通過電子快門的迅速切換,極大的降低瞭自然光的疊加榦擾與延遲誤差。揹景譟聲和穩定性試驗測試結果錶明,應用該繫統使平均光子計數的譟聲偏差不超過4.5 cps,5次重複測試的相對誤差為0.7%,重複測試的延遲髮光麯線具有良好的重閤度。對萌髮玉米延遲髮光的測試結果錶明,延遲髮光麯線的擬閤優度R2在0.99以上,應用該繫統可以得到較為理想的結果。
침대목전생물연지발광검측계통이용외치격발광원존재적연지오차화자연광첩가간우도치적측량결과중복성불호화가고성차적문제,설계료일충생물연지발광복조광원계통。해광원계통주요유항온복조실、삼기색RGB-LED(light-emitting diode)구진복조광원、전자쾌문격리기급공제전로조성,병여BPCL계렬미약발광측량의조장재일기사용。재51계렬단편궤적공제하,해복조광원계통실현료광원빈솔화광강적다중선택이급복조시간적정서화조작,실현료광조여검측지간재동일개암실통도중통과전자쾌문적신속절환,겁대적강저료자연광적첩가간우여연지오차。배경조성화은정성시험측시결과표명,응용해계통사평균광자계수적조성편차불초과4.5 cps,5차중복측시적상대오차위0.7%,중복측시적연지발광곡선구유량호적중합도。대맹발옥미연지발광적측시결과표명,연지발광곡선적의합우도R2재0.99이상,응용해계통가이득도교위이상적결과。
The analysis and application of biological delayed luminescence is a hotspot in many interdisciplinary areas. However, the irradiation source of biological delayed luminescence has not been thoroughly investigated. In order to solve some problems of the current biological delayed-luminescence detection system, including the poor repeatability and reliability caused by the delay error of the external excitation light source and the superimposed interference of natural light, a biological delayed-luminescence irradiation source system is presented in this paper. This irradiation source system mainly consists of a constant temperature irradiation chamber, a tricolor RGB-LED matrix irradiation light source, an electronic shutter isolator, and a control circuit. The irradiation source system is assembled with the BPCL Series weak luminescence meter. The proposed system has technical improvements in three aspects related to the external excitation light source. 1) It features multiple automation selections in irradiation frequency, irradiation intensity, and programmable irradiation timing. Under the control of the MCS-51 single-chip microcomputer, 16 light spectra with varying chrominance can be selected in the range of 410-625 nm, with LED driving current adjustable from 16-40 mA for different brightness, and the irradiation time is adjustable within the range of 0-999 s. 2) It features fast switching of the electronic shutter in lighting and detection process in the same channel of a darkroom. When the light source is on, the shutter is closed automatically. During measurement, the shutter is opened automatically when the light source is off. It therefore reduces the superimposed interference with natural light and the delay error. 3) Because of the temperature sensitivity of the biological delayed luminescence, a temperature sampling circuit called the ‘single integral type A/D converter’ with a simple structure is designed based on the working principle of the‘double integral type A/D converter’. Combining with the MCU, this temperature-sampling circuit works as a temperature controller, which can maintain a constant temperature in the sample chamber. After using this irradiation source system, the results of the background noise and stability testing showed that the noise deviation in average photon counting was less than 4.5 cps (counts per second). The relative error in five repetitive tests was 0.7%, achieving a high repeatability of the delayed luminescence curves. The test results of the delayed luminescence in germinating corn further showed that the R2 of the delayed luminescence curves fitting was greater than 0.99. Good reliability and repeatability can be achieved in this system.