Thank you for purchasing the MSG Equipment product.
Tester for diodes and rectifiers is manufactured from quality components and materials.
This manual contains information about the purpose, configuration, design, operation, technical
characteristics and operating rules of MSG MS021 tester.
The manufacturer reserves the right to change the design and software without prior notice to
users.
Read carefully this manual before putting MS021 (hereinafter referred to as the “Device”) into
operation, get special training at the equipment manufacturing facility if necessary.
MS021 has been engineered to satisfy the demand of big service stations and alternator repair
shops for the device which would allow quick and accurate rectifier health checks. Testing
rectifiers with the use of multimeter has always been the most common practice.This method has a
significant drawback -it doesn't help to identify the diode type and find the faulty one. The test
current of a standard multimeter is about 0.002A, which is too low compared to the diode
operating currents.The test current of MS021 is 0.9A which allows accurate diagnosingof a diode.
2
MS021 is designed to test the performance and structural integrity of automotive alternator
rectifiers as well as of diodes separately.
The device detects:
-type of a diode (standard or avalanche);
-degradation of a diode (excessive forward voltage drop);
-avalanche diode reverse-breakdown voltage;
-diode breakdown;
-diode open-circuit failure;
-poor contact between the diode and the conductive busbars.
INTRODUCTION
1. PURPOSE
User Manual - MS021 Tester
English
