Gas measurement is without a doubt the most important part of confined space safety. Do it right, and you and your crew go home at the end of the day—do it wrong, and you might never go home again! So if you're a newbie (or even a little rusty), you've got to do your homework. Here's the first lesson: get the right tools! If you already have a gas monitor, take it out and look at it. Without this device you are nothing! It always has to be with you in any confined space — no excuses! But make sure you have the right kind of monitor. A single gas monitor, for example, won't give you enough information to enter a confined space safely. You're going to need a pump-equipped gas monitor that tests for at least three common problems: dangerous oxygen levels, explosive gases and hydrogen sulfide. Why so broad? Because you can never know what a confined space will throw your way. We applaud you if you've already got a multi-gas monitor with a pump. Really, we're clapping wildly! But make sure you use it correctly. Always test multiple parts of your space. What do we mean? Well, the the thing about the three gases we look for is that they often collect in different zones. Notice that in this scenario explosive gases gravitate toward the top of a confined space. Only test the bottom of a space, and risk blowing yourself to kingdom come. Only skim the top, and you chance missing hydrogen sulfide or dangerously low oxygen levels that could make you keel over. In short, skipping zones is a bozo move. These lessons are pretty simple, but unfortunately far too many confined accidents happen because people throw basic safety precautions out the window. So, as simple as they might sound, they'll help keep you and your team safe if you follow them. No doubt, there's still a lot more to learn, but we're here to help you along. Have particular concerns? Feel free to leave them in the comments section below.