摘要
采用离子选择电极法测量溶液中某种离子的离子浓度时,离子选择电极与参比电极间产生一个电势差。基于电势差信号的低频率、低幅值和输入高阻抗的特点,设计了一种用于离子选择电极信号采集的前置放大器。该放大器主要由传感器电极、低通滤波电路、超高输入阻抗放大电路、差分式放大电路和50 Hz陷波电路等组成。该前置放大器提供了高达1012Ω的输入阻抗,并且很好的降低了共模信号的干扰以及工频干扰,可以较好的采集到离子选择电极的微弱信号。
When use anion-selective electrode method to measure a certain ion-concentration, an electrical potential difference is generated in between the ion-selective electrode and thereference electrode. A prime amplifier forthe electrical potential difference is designed based on the signal characteristics of low frequency, small amplitude and high resistance. The amplifierincludesan electrode, low pass filter circuit, ultra high input resistance amplifier circuit ,differential amplifier and 50 Hz rejector circuit. This prime amplifier provides 10^12Ω high input impedance, and can well remove the interference of common mode signal and interference of power frequency. Therefore, itcan be very goodto collect the weaksignal from the ion-selective electrode.
出处
《电子设计工程》
2014年第11期12-14,18,共4页
Electronic Design Engineering
基金
江苏省产学研联合创新资金-前瞻性联合研究项目(BY2012070)
江苏省环保科研课题(2012051)
关键词
离子选择电极法
超高输入阻抗
前置放大器
工频干扰
ion-selective electrode method
ultra highinput resistance
prime amplifier
disturbance of industry frequency
