Design And Implement Of Measurement System For Weak Current

With the development of science,the technique of weak current measurement and detect is indispensable.Weak current measurement technique is used in many fields and its development plays an important role in relate fields.Circuit for pA measurement was designed by analysia in weak current measurement method in this paper.By being analyzed two ordinary ways which are transition for current to voltage and current to frequency. Transition for current to voltage will be improved to the I-V convertor of T feedback resistor network. This method overcomes the resistance of the introduction of large high-noise and shortcomings of distributed capacitance.Reducied the system'error, Improved real-time measurement system,had the function of measure the non-DC. Electric charge for weak current worked for a long time will be measured, put up with a viable, cost-effective,a good way. Through a simple and practical I-F converter circuit, Overcome the spread of electronic components caused by interference and compatibility issues, greatly reduces the system's linear error.In the weak current detection technology, the main consideration in the effective are suppression of noise under the condition of the weak current signal conversion and acquisition,To achieve the weak current signals into data. This paper presents the conversion of the weak current to voltage output detector circuit is to convert the weak current detection voltage to achieve;The number of points raised by the current detector output is converted to the charge number of the realization of pulse measurement. These circuits are simple, practical, easy to design and regulation.The whole circuit system has many characters such as small rxcursion,good linear ratio,stability, easy to use etc.