[music] Hey, yall! This is Dr. Know-it-all. This channel is dedicated to finding out whether I really do know it all or not. Make sure you ask questions in the comments or at my email address, which is in the description or at the end of the video. So watch the video there. You go, alright? Um, one thing, just real quick. I apparently don’t know how to walk. I tripped yesterday and bash my head into the grill outside in the back. Sorry about that. I get to live with that for a couple of weeks until it heals up. Alright, without further ado question of the day. Drumroll please. Oh, alright, okay, maybe. I can help with this, so thank you for the question. The question is, what is an HRV. And why is it different than the normal crown? I can’t find out what the differences are so. Okay, so that has to do with the this kind of watch, which is a dive watch, so I, fortunately, I’m wearing it, so I get to just pop it out. I don’t have to stop the video. So here is my Omega Speedmaster. This is a dive! Watch so there you go. Let’s see if it focus on that. Alright, so as we can see here. There are two crowns on this rather than one. The first crown is what you would call your normal crown on a watch and that is the one at the three oclock position. Then there is what’s called the helium release valve, which is here at the ten oclock position. Okay, so they do very, very different things. Okay, the first one. Well, actually, Yeah, let’s talk about this one first. So this guy right here. The regular crown is a screw down crown, which means that you actually have to unscrew it to operate it, right, The reason why you have to screw it down is because this watch is a dive watch. It’s rated to 300 meters as you can. Maybe make out on anyway. It’s 300 meters. If you didn’t have a screw down crown, which basically locks it into place and pushes on an o-ring, then it wouldn’t be able to withstand those kinds of depths, so that’s a screw down crown, but other than that it acts as a normal crown on a normal watch. Which means that if you unscrew it, you can wind the watch, right. It does have an automatic winder on it. So as you like, wear it and move the route watch around it winds itself, but it also has the ability to just turn it and wind it as a normal watch. This is a mechanical watch. I will put a couple of cards up here so you can look at that. I have other episodes concerning that, and that means that it actually has a spring inside that has to get wound up. So you need to wind it. So the number one function for this crown is to wind the watch number two. If you pull it out, one stop. There is a date on the bottom there as you can see. Maybe it’ll focus. So it’s the sixth vapor right now, anyway. If you pull it out, one stop, you can rotate the crown and it will change the date and so six seventh. Whatever you can change the date to whatever your heart desires the the third stop out or the second, stop out. Sorry, is the the hacking and time setting thing. So if you pull this out all the way it will stop the watch, a second hand from running, and then you can turn it and you can adjust the time as you’re going here. So right, so that’s a pretty normal crown utilization. If you own any automatic or manual wind mechanical watch, the crown will do that now. Some older watches don’t have the date quick set. So that means that you have to, actually, you know, like, let’s say it’s actually the 20th and the watch is on one. You have to wind it through 24 hours like 19 times to get it caught up with that. So the date quick set is actually a very nice complication. So anyway, that is main crown here. Hrv or helium release valve. Right here is the secondary crown. This crown is totally unnecessary unless you’re a saturation diver, which is just a tiny fraction of the universe. Okay, so that would be people who work on oil rigs or communications cables or electrical cables, things that are buried underwater right under the ocean, usually on the seabed floor or sticking up, like if you work on an oil rig and you have to go dive down. What happens is people who do that for a living will actually go at depth for a long period of time, like perhaps 30 days or something and what that means is that they’re put into a little kind of not spherical, it’s kind of cylindrical with, like, rounded caps. I’ll show a picture of it. But anyway, they’re inside of this small space and it’s pressurized up to the pressure of the water at the depth. They’re at, so lets either. Let’s say they’re diving at a hundred meters. They will then, or that’s 333 feet. I think something like that anyway. They will pressurize the air pressure inside of this container to the same equivalent of water at 100 meters. If you’ve ever dove down even in a pool. Even if you don’t dive like you dive down in your ears, start to pop like they get squished or certainly if you’ve scuba dived. Of course you have to, like, hold your nose and clear your ears because the water pressure is very heavy and so every time you go down about 10 meters or 33 feet or so the the pressure of the water doubles. So you go from something like, you know? One bar or 15 psi to two bars or 30 psi, and it goes up every every time you get out. So 100 meters is a very, very low depth and in order to dive to that depth, you would have to spend an inordinate amount of time decompressing when you come up, so let’s say you went from the surface. You’re on a boat, you dive down to a hundred meters and I can’t do the calculations in my head right now, but if you were there for like, 20 minutes, you would probably spend five hours coming up decompressing so that’s like an entire day for 20 minutes of work. That’s not very useful, so decompression Divers live in this environment, that’s super pressurized, so that what they do is then they get transferred out and go down under the water to a very deep depth and then they pop out of their little bubble and they go out. They do their thing at a hundred meters. They fix whatever stuff they’re gonna do for, like, six hours or something like that. Then they come back in to their bubble, and then that gets transferred back to their main container that they live in, which is kind of like a small apartment complex and they’ll stay there for thirty days, and then they have to decompress for goodness knows. I think it’s like three days. They have to decompress. It’s a very, very long period of time. They sound super funny because I have to put a lot of helium into the atmosphere because oxygen becomes toxic at high pressure. So there’s a whole bunch of it’s very, very intriguing. And if anybody wants to ask a question about all the details of decompression diving. I’m happy to talk about that too, because that’s super cool, but anyway, so that is a long way around to a short answer, which is that this is only useful for decompression divers. So what happens is they found out When decompression diving started in the 60s like Rolex and Omega and other companies were making dive watches and they would go down. They get pressurized. They would do their thing and when they started to come back up and depressurize what they discovered was helium which was like. I said they have to put a lot of helium. Into the atmosphere to keep the oxygen toxicity down while helium is a tiny tiny molecule because it’s only made of two protons and two neutrons and it would slip in to these areas inside, Even though, like the crown is a screw down, and even though this is sealed, it would slip inside of this, and the watch would become pressurized to the ambient pressure of a hundred meters down and as they depressurized it, The crystal eventually would go ping, and it would just shoot off because there would be so much pressure inside the watch that it would overpressure the inside of the watch. It wouldn’t have time to escape because they’re, you know. Depressurizing rapidly and the crystal would shoot off, so they went. Oh, so there was a couple of different solutions that were proposed. I think it was actually Rolex. That came up with this first, but the helium release valve. Rolex actually has a little tiny like automated thing here, which is a little tiny button on the side and that just when it gets to be too high, a pressure it just goes and it just releases some Omega on the other hand. Have an actual screw down thing, right, so you unscrew this and when it unscrews and actually, I don’t know if you can see that there, but there’s little red bar that shows you. Then don’t take this diving right now because it’s open, so you screw it back in anyway, so it unseals it to some extent. Remember, you’re inside of an air chamber, so it’s releasing the helium into air. It’s not releasing it into water, so the only time you would use, This is if you’re a compression diver and you’re in atmosphere, not water, and you’re coming up. You’re decompressing then you would unscrew this and as the pressure releases outside of you and that this becomes higher pressure again like a balloon, it will release it out of here, so it’d be like having a balloon and having like the little valve on the balloon so rather than just holding the balloon tight. And as the pressure releases, it gets bigger and bigger until it goes boom. And it pops this way. It’s like opening up the valve a little bit and letting some air out. So that’s what that does, that’s, that’s all. The helium release valve. Does it’s honestly. I mean, unless you’re a compression diver, this is useless! It’s a cool thing on these watches. I think that a lot of people like Rolex better. Because what Rolex does is they again? They have just a little tiny dot on the side. It’s just a little a little circle that has a valve that pops out when it needs to. This is kind of more of a manual thing, but this has become kind of a calling card of Omega watches that they have this helium release valve. So at least on the Seamaster professional! They have that, so that’s a thing. Ironically, I to get back to the earlier story when Rolex came up with a helium release valve. The Omega plop roof, which is plunger professor. Nala, sorry, my French pronunciation is a little bad right there. Close your professional there. We go anyway. If what they did instead was, they made a monoblock case and I’ll show a picture of this. That means that the entire thing, except for the crystal itself is all one piece of aluminum, and so it’s very, very, very strong. No air is gonna get in there at all. So the only thing was the crown and the and the attachment of the crystal here around the outside, and they just sealed that up super super tight with a with a multi baffle and so no helium could get in so they didn’t have to have a helium escape valve so kind of ironically, This is like Omega’s calling card, but the plop roof, which was omega’s answer to the Rolex. Sea-dweller didn’t have helium helium release valve so there. You go kind of a weird thing, but so hopefully that answers your question in a very long-winded way. This is a normal crown. It seals up by by screwing down. It pulls out. You can wind the watch. You can pull it out one more time. You can set the quick date. You pull it out one more time at hacks, which means the second hand stop, and you can set the time. Then you push it in you. Screw it down the helium release valve only useful if you are compression diver, and you need to decompress yourself and your watch, and then you would unscrew it. And during the time that you were decompressing, the helium would release as you go, so there you go. That’s the difference between the two very long-winded answer. Hopefully that was useful. If you liked the video, make sure you like the video. Click the thumbs up thingy and subscribe to the channel for more and definitely make sure you ask more questions in the comments or at my email address, Which is Dr. Know-it-all nose at gmailcom till next time. Bye bye. [MUSIC].