rolex1016 白金會員 
註冊時間: Dec 05, 2003
文章: 2218
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發表於: 星期二 2004-03-16 21:17
文/朱丕傑
筆者看過一位很資深的潛水員潛水上岸後，拿牙簽推他手腕上勞力士潛水錶(Sea-Dweller 1220m)的排氦閥，筆者很好奇請教他原因，“我剛才下到四十米，所以在洩壓”他揚揚眉毛回答著………。
一般我們所看見的潛水活動稱為水肺潛水，也就是背負充滿壓縮空氣的氣瓶在水面下活動。大多數的潛水活動所背負的氣瓶內所裝載空氣成份仍與自然空氣相同，比例中以氧氣佔五分之一，氮氣約佔五分之四。其中的氮氣在正常氣壓時對人體並沒有甚麼影響，但在高壓下氮分子會融入神經細胞而造成不同程度的麻醉性，大約水中30公尺的壓力時停留一個小時的時間就會開始產生麻痹現象,即所謂“氮醉”。而氧分子在水中30公尺的壓力停留大約一個小時以上時會影響腦部而造成氧中毒，故純氧也不適合深海或長時間的潛水使用。
所以在某些情況下，潛水者在深海中需要停留相當長的時間時，常以氦氣取代氮氣，並且依適當的比例使用氦-氧混合氣體。氦氣的優點在於會溶解於體內的氦氣只有氮氣的百分之四十，而且氦分子的體積非常小，使其擴散速率是氮氣的2.5倍，所以使用氦-氧混合氣體不但可以減少麻痹現象，也可以減少減壓上升的時間。
有這些初步的瞭解，就可以談一談潛水錶為何需要排氦閥了。對深海潛水或長期在海底工作的人，使用氦-氧混合氣體是較為有利的，但筆者曾提到氦分子的體積非常小，甚至小於水分子許多倍，所以在使用氦-氧混合氣體的環境時，氦氣有可能在外界的高壓下而進入手錶內，即使是高防水性的專業潛水用錶。
特別在使用轉移艙--母艙(PTC--DDC)的飽和潛水作業時，氦氣侵入手錶的機率更高。此種作業方式就是潛水人員先在工作母船進入轉移艙，由纜繩控制進入海底，到達目的深度後再離開轉移艙在該區域作業。回程時先進入轉移艙，回到工作母船時直接銜接加壓母艙，可使減壓過程能在水面上完成。
在深海中氦氣因外界高壓進入錶殼內，就會使得錶內壓力相同於外界高壓，相反的一但潛水人員上升時，將形成錶殼內部對外產生壓力。1966年日本就發生配帶300米防水潛水錶的潛水人員，在350米深海潛水作業，上昇過程時錶殼爆開。自此，各品牌潛水錶的開發才開始重視氦氣的重要性。
由於氦氧潛水歷史並不長，所以各家錶廠對付氦氣的方式都是各顯神通，都有自己的一套理論，至於何者最佳，暫時是很難有結論的。
ROLEX Sea-Dweller 勞力士
在1926年製造出了世界第一台防水錶，之後就對潛水用錶的開發上不遺餘力。1960年勞力士曾經製作一只實驗用的潛水錶款，外掛在美國海軍TRIESTE號上，並潛入世界最深之馬里安那海溝達10908公尺，自此奠定了勞力士在潛水錶中的龍頭地位。
1971年勞力士開發出具備排氦氣閥防水610公尺(2000英呎)的Sea-Dweller，隔年初在法國馬賽海域就由M. Patrice Chemin與M. Robert Gauret在氦氧混合氣環境下配帶此一錶款創下潛入海中2000英呎(約600公尺)連續18天的世界記錄。1980年Sea-Dweller改為1220公尺防水至今。現在配備Sapphire藍寶石水晶鏡片，具瑞士官方天文台證明自動上鍊機心，日期顯示。排氦氣閥置於左側，當錶殼內氣壓力大於外側時，會自動將閥門頂開排出氣體，卻又仍能保持其防水性。所以請配帶這款錶的潛水者不要再拿牙簽推排氦閥了。
 自動排氦氣方式
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MichaelC 分區版面管理員 
註冊時間: May 25, 2003
文章: 299
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發表於: 星期二 2004-03-16 21:37
朱丕傑  ........................敦文的朱sir
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PATRICK 終極會員 
註冊時間: Feb 07, 2004
文章: 8673
來自: 日本東京
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發表於: 星期三 2004-03-17 08:26
我的最愛 !
16600 SD
PATRICK
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tourbillon5102 初級會員 
註冊時間: May 14, 2004
文章: 26
來自: united states
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發表於: 星期五 2004-07-23 16:20
This is total non-sense, you have never been to Nitrox diving
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isaac_sun 資深會員 
註冊時間: Oct 29, 2003
文章: 595
來自: 台北
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發表於: 星期五 2004-07-23 16:46
說的沒錯............想補充一下
空氣中約有78%的氮(惰性氣體)
21%的氧與 1%的雜質(不知道是什麼)
在高壓下氮分子會融入血液中而造成有類似醉酒的狀況,
如不在水中完成完整的減壓程序而快速上升的話;血液中
的氮氣會結成氣泡來衝擊身體組織,由於身體會因劇烈疼
痛而成彎曲狀,故被戲稱為彎曲症,這就是潛水夫病!!
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calatravayang 榮譽版面管理員
註冊時間: Jun 14, 2004
文章: 4073
來自: 台北
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發表於: 星期五 2004-07-23 17:15
| isaac_sun 寫到: | 說的沒錯............想補充一下
空氣中約有78%的氮(惰性氣體)
21%的氧與 1%的雜質(不知道是什麼)
在高壓下氮分子會融入血液中而造成有類似醉酒的狀況,
如不在水中完成完整的減壓程序而快速上升的話;血液中
的氮氣會結成氣泡來衝擊身體組織,由於身體會因劇烈疼
痛而成彎曲狀,故被戲稱為彎曲症,這就是潛水夫病!! |
氮氣應該不是惰性氣體喔，那是指氦氣那一類的 :Q
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tourbillon5102 初級會員
註冊時間: May 14, 2004
文章: 26
來自: united states
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發表於: 星期五 2004-07-23 18:17
Nitrogen 是惰性氣體啦, 但是如果象rolex1016说的是beach dive, 是不会用到排氦閥的,
事实上, 用到排氦閥只有deep sea saturation dive. 彎曲症的氮是从scuba tank来的, 表里是不会有nitrogen的, 应为表在水里. 其实和equalize的道理是一样的. 对表来说, scuba就象skin dive, 是不需要equalize的
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calatravayang 榮譽版面管理員
註冊時間: Jun 14, 2004
文章: 4073
來自: 台北
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tourbillon5102 初級會員
註冊時間: May 14, 2004
文章: 26
來自: united states
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發表於: 星期六 2004-07-24 02:13
nitrogen在英文里是inert的说， 好象中文是惰性的意思把？
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Etacaa 中級會員 
註冊時間: Jul 16, 2004
文章: 110
來自: San Francisco
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發表於: 星期六 2004-07-24 02:57
Man, I am totally confused now. We are talking two different kinds of "deep diving": (1) really dive in person, e.g. your watch has direct contact to ocean water (2) "dive" with a man-made machine but without direct conact to ocean water, e.g. stay in an underwater station for oil digging
In (1), the probability of air getting into the watch is very very very small. It is relatively "vacuum" inside the watch, compared to the outside pressure created by the water. Two things are critical. First, the seal has to be very good because the water is being "pushed" by many ATM against the seal. Secondly, the case and glass have to be very strong. Otherwise, the watch will crash.
In (2), air getting into the watch varies, depending on the air mix and air pressure maintained inside the chamber. In an underwater facility, the air pressure is the same as the water pressure outside, e.g. many ATM. The air is typically mixed of Oxygen , Nitrogen, and Helium. The probability of Helium getting into the watch is high, especially those underwater workers tend to stay in the station for many days at once. When the workers decent to the surface, they need to go through a series of decompression procedure. Otherwise, they will die. Please note that I said "workers", not "divers", because the persons may not really get into the water. They can be dry all the time. During the decompression procedure, the Helium inside the watch may not have enough time to "find its way" out of the watch. The pressure difference builds up. A "big" valve helps to release extra pressure quickly. Well, the valve doesn't just release Helium. It release Oxygen and Nitrogen too. The valve is called "Helium valve" because Heilum has the smallest particle structure (therefore, the highest probability of getting into the watch) and causes the problem most the time.
So, what the "experienced dive" did in rolex1016's story was very misleading, regardless if he used Nitrox or not. First, where did the Helium inside his watch come from? Even if he just referred to "releasing air", where did the excess air come from? Secondly, why did he need to poke the valve? The valve works automatically.
You see. This is exactly the problem why I find it amazing that people rush to buy 16600. Most buyers didn't even know what they are buying. The strong case and Helium value are useless, except for very few deep-water people. You'd be better off wearing a buck of steel - waterproof to 10,000M+. On the other hand, why do people wear diamonds, which have virtually no use in daily life? I guess people just want to feel good by wearing something special. Well, in such a case, I'd recommand spending a little bit more money to get a two-tone Sub. It looks much nicer.
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