Pressure

I was talking to Lloyd this morning while he was calibrating some pressure sensors. We make two kinds of pressure sensors. He was working on the older model, which requires a special jig to pressurize the transducer. The transducer on the new sensor has a little tube sticking out from one side, about 1/16 on an inch in diameter. For this sensor, he only has to slip a plastic tube over it. So how much pressure are we talking about here? The sensor is good to a depth of 60 feet (of water), which is about 30 psi (pounds per square inch). The cross section of the inside of this plastic tube is pretty small. Using our formula for area (PI x R^2) we get about 1.5 ounces of force. Not very much. No wonder the tubing does not need a clamp.

A while back I stopped at the Lancair factory in Redmond and talked to a couple of people who worked there. They were telling us about pressure testing the cabin for the Lancair IV. They took the pressure up to 5 psi, and all was well. They took it up to 10 psi, and everything was still fine. I believe that is all that is needed for aircraft. Then they took it up to 15 psi, just to see if it would hold, and people started leaving the building. Imagine what would have happened if there had been a catastrophic failure. Could have been a big bang.