AC Milliammeter, Model J0414, is suitable for the laboratories of middle schools and polytechnic schools to measure current intensity in the AC circuit.
Model JO415 DC microammeter is suitable for students to measure weak current and slimelectric potenial in laboratory of middle school and polytechnic school.
As you know, at a polytechnic, you follow broadly similar courses of study to those at universities, although many polytechnic courses are strongly vocational.
Some of these courses are the so called " sandwich" courses, typically two years' polytechnic study, one year in industry, and a final year back at the poly before your examinations.