A long-time current integration digitizer was developed for monitoring ion beams of the Heavy Ion Research Facility at Lanzhou(HIRFL).A simple and practical method for current/frequency conversion was adopted

combined with a counter and processor.Being able to measure input currents of 10 pA?10 μA

the long-time digital current integration instrument can be used for testing current or electrical charge from the ionization chamber

Faraday cup and other weak current sources.The time of measurement can be selected from 1 second to 192 hours(8 days).The instrument can be operated in one cycle mode and recycle mode.A feasible

general

and cost-effective way for long time test of current or electrical charge was presented.