量程可以手动调节的数字电压表，有10V和5V两个档位，当测量小电压是用5V档，当测量大于5V于10V的电压时用10V档-You can manually adjust the range of digital voltmeter, 10V and 5V have two stalls, to measure small voltage is 5V file used when measuring greater than 5V 10V 10V file at the time when the