Membrane Kit for Dissolved Oxygen Meter works well in establishing air quality, especially if you ensure that the components are well maintained and replaced or calibrated when necessary. The Extech DO603: Membrane Kit for Dissolved Oxygen Meter gives you a replacement screw-on membrane kit to keep the DO sensor in top shape. 

In the Extech membrane kit, you will be provided with six screw-on membrane caps, which allows you to use your oxygen-measuring device for a long period of time, before having to make further changes. You’ll also be provided with polishing paper, and a 15ml bottle of filling solution. You’ll basically have everything you need to make sure that your oxygen measuring device gives you accurate results at all times.