Connected Safety For Confined Space Entries
Transcript
Hello again everyone. I'm Justin Denson with Blackline Safety. Today, I'd like to continue my discussion of using pumped portable gas monitors for confined space entry and confined space monitoring. Focusing on two crucial aspects to get the most accurate readings from your gas monitor.
Before I jump into those though, let's talk about gas stratification real quick. Within confined spaces, gases distribute unevenly due to their different weights as compared to normal atmosphere. This means that some gases are going to accumulate at the top, some will accumulate in the middle, and others will accumulate at the bottom.
To ensure thorough sampling, it's recommended to take samples at different levels approximately every four feet. And OSHA additionally suggests testing the area around the worker, extending four feet in any given direction of travel from side to side. Okay. So now that we understand that gases are going to distribute unevenly in a confined space, let's talk about how we sample for those in proper sample time.
When you're using a probe and tubing with a pumped portable gas monitor, it takes time for that gas to travel through the probe and the tubing. And then it also takes time for the sensors to react. A good general rule of thumb for gas transport time through your tubing is two seconds per foot of line. And then you want to give another two minutes for the sensors to be able to fully react and stabilize to whatever those readings might be in that given section of confined space that you're sampling.
So let's take example ten feet of tubing. If I'm using ten feet of tubing, I know I need to allocate twenty seconds just for the gas to reach the sensors. And then I need to allocate another two full minutes so those sensors have time to stabilize on what those readings could be.
Mastering and understanding tubing length and sample time is absolutely key to precise gas detection and confined space. Sticking to these best practices will minimize risks.
Thank you for attending and I will see you guys again real soon. Thanks again.