Model JO415 DC microammeter is suitable for students to measure weak current and slimelectric potenial in laboratory of middle school and polytechnic school.

JO415型直流安培于中学、中专等学校实验室，可测微弱电势。

For electrical properties of MOS capacitors, the C-V curves were obtained by LCR meter (HP4284A), and picoampere meter (HP4140B) was used to measure the J-V curves.

另外以电电容电阻仪(HP4284A)进行C-V测；以微安培仪(HP4140B)进行J-V测。

The main structure have:Electromagnet and Heng galvanism source, numerical type Gauss account(the effect of Huo Er) and ammeter and volt account, have control dish of illuminate the system.

电磁铁和恒流电源、数字式高斯 （霍尔效应）、安培和伏特、配有照明系统的控制盘。