Pretest is to the product sample or prototype in advance according to the standard before the product sent to the Certification Institution , which can help save your cost of continuous failure and retest.

Great One has all kinds of testing equipments , ex :Hi-Pot Tester , DC Power Supply , Grounding Resistance Tester , Leakage Current Tester , Temperature Recorder , Power Meter , UL Rain-Test Room , Oven , Chamber , Push/ Pull Force Gauge , etc., to do complete testing conforming to the standard of your products.