OHD is a company committed to our Mission of Passionately Protecting The Health Of The World's Workforce. OHD provides a range of products and services to help you protect your employees and manage your occupational risks. Whether you are looking for the revolutionary QuantiFit2 fit tester, QuantiCheck user seal check device. Noise Dosimeters, Audiometers or Sound Level Meter, we can provide you with a complete safety and health solution.