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

JO415型直流安培计适用于中学、中专等学校实验室，可电势用。

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.

另外以电电容电阻计量仪(HP4284A)C-V线量；以安培计量仪(HP4140B)J-V线量。

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、数字式高斯计 （霍尔效应）、安培计和伏特计、配有照明系统的控制盘。