188V 
188v la mot gia tri dien ap la 188 volt. Trong he thong dien, dien ap la do do giua hai diem. Gia tri nay co the xuat hien do lech khi nguon dien thay doi, tai hoac load phat sinh su thay doi do dong.
Goi la gia tri thu do bang man hinh do cua nguon dien, 188v thuong la tam hieu cho cac khoang song dien mang. Nguon lam day co the la bien doi phat ra do dong, do tai, hoac su dung cua dong dien nho hon. Quan trong la nhan biet do lech voi muc nap mac dinh de dam bao an toan.
De do 188v mot cach an toan, dung dung cu do dien tu chuong, khong dung tay vao cac thanh phan gac vi tri dan. Su dung multimeter hoac oscilloscope co chuc nang do, dung cam ung chung dat, an toan chuan, va dung bien chung bao ve. Luon thao tac rieng trong khu an toan.
Trong thuc te, 188v co the dung cho kiem tra do do cua nguon dien, lam tham chieu do do cho thiet bi mang, hoac lam nguon cho cac doan test dien. Nhung can luon dam bao an toan va dinh vi dien ap phat huy.
