This standard specifies the technical requirements for decompression of diving (air diving) using compressed air as the breathing medium. This standard applies to the selection of decompression solutions for air diving within a diving depth of 60m, and also applies to the selection of decompression solutions after exposure to compressed air in a pressurized chamber. GB 12521-1990 Technical requirements for air diving decompression GB12521-1990 Standard download and decompression password: www.bzxz.net
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National Standard of the People's Republic of China Technical requirements for air diving decompression1 Air diving) decompression technical requirements. GB12521-90 This standard applies to the selection of decompression solutions for air diving within a diving depth of 60m, and also applies to the selection of decompression solutions after exposure to compressed air in a pressurized chamber. 2 Terms 2.1 Diving depth divingdepth The maximum depth reached by the diver during diving, measured in meters (m) of the height of the sea water column. When a diver is exposed to compressed air in a pressurized chamber, the pressure is equivalent to the height of the sea water column as the diving depth. 2.2 Underwater working time bottomtime The period of time from when the diver enters the water to when the diver completes the diving operation and begins to ascend, measured in minutes (min). 2.3 Decompression The process in which a diver gradually returns to the surface or normal pressure according to prescribed procedures and requirements after being exposed to compressed air during air diving or a pressurized chamber. 2.3.1 Underwater stage decompression: The decompression process of a diver in the water is divided into rising, staying, rising again, staying again, until returning to the surface, when the decompression ends, it is called underwater stage decompression. When implementing underwater stage decompression, the breathing medium can be compressed air or medical oxygen. 2.3.2 Surface decompression: Most or all of the diver's decompression process is performed in the surface pressurization chamber after leaving the water, which is called surface decompression. When implementing water surface decompression, the breathing medium can be compressed air or medical oxygen. 2.4 The decompression schedule decompression schedule specifies the decompression steps and schedule according to the combination of diving depth and underwater working time. 2.4.1 Basic decompression schedule is a decompression schedule selected based on the diver’s actual diving depth and underwater working time as the basic parameters. 2.4.2 Extended decompression plan modified decompression schedule When the outside world or/and the diver himself has some or some factors that are not conducive to safe decompression, the decompression plan needs to be extended on the basis of the basic plan. At this time, the decompression plan is The plan is called extended decompression plan, 2.5 stop decompressionstop In order to gradually discharge the high-tension nitrogen from the body during decompression, the diver must stay at the specified depth for a certain time, and the specified stop depth is called a stop. 2.6 First stop firststop The stop with the largest depth specified in a decompression plan is called the first stop. 2.7 Time to first stop: The time from the completion of the diving operation to the time the diver reaches the first stop, measured in minutes (min). The State Bureau of Technical Supervision approved the implementation on 1991-08-01 on 1990-12-03 2.8 stoppage time GB12521-90 When a diver decompresses, he arrives at a stop station and leaves the station. Stop time. Measured in minutes (min). 2.9 The total decompression time totaltimefordecomptession is the sum of the time to rise to the first stop, the stay time at each stop, the 1-min transition time between each stop, and the 1-min time to rise from the 3m station back to the water surface. 2.10 Suitable diving time limit limitingline In order to ensure the safety and health of divers, the decompression table stipulates the underwater working time limit that should not be exceeded for different diving depths. 2.11 Surface interval time surfaceintermittenttime is the sum of the time it takes for a diver to rise from the last stop in the water, return to the surface, unload, and enter the pressurization chamber to pressurize to a predetermined pressure when performing surface decompression, measured in minutes (min). 2.12 Repeated diving repetitivedive A dive performed within 12 hours after a dive. 2.13 Residual Nitrogen Time When selecting a repeated diving decompression plan, a time amount expressed in minutes (min) needs to be added to the underwater working time of repeated diving to represent a certain amount of remaining nitrogen in the diver’s body after the last dive decompression. To measure the influence of nitrogen, this time is called the remaining nitrogen time. 2.14 Surface interval time surfaceintervaltime is the time from the end of the last dive decompression to the start of repeated dives. 3 Technical requirements for air diving decompression Select the decompression plan according to the following classification requirements and the air diving decompression table (see Appendix A (reference part) for instructions). Air diving decompression table diving depth m 12 15 18 underwater work| |tt||Working time min 360 105 145 180 240 300|| tt||45 60 80 105 145 180 240 rose to No.|| tt||Time of one stop
min 2 2 2 2 2| |tt||2 3 2 2 2 2 2 2||tt ||36 a Stop depth, m 21 Dwell time, min 3 10||tt| |3 8 9 18 10 14 15 16 5 1 16 20 26 23 Decompression Total time min 2 2 13 17 22 30 3 80|| tt||17 23 32 38 51 Repeated Dive Water Retrieval Symbol|| tt||M M o z * H K L||tt| |N Z z diving depth 21 24 27 30 Underwater work Working time min 35 45 60 80 105 145 180 240 25 35 45 60 80| |tt||105 145 180 240 20 25 35 45||tt ||60 80 105 145 180 15 20 25 35 46 60 80 105 145 180 rose to No. Time of one stop
水下工 作时间 min 5 10 15 20 25 35 45 60 80 105 5 10 15| |tt||20 25 35 45 60 80 5 10||tt ||15 20 25 35wwW.bzxz.Net 45 60 80 是以到第||tt ||一电影站 time min 8 7 7 6 6|| tt||5 4 4 3 3 8 7 7||tt| |6 5 5 4 4 3 9 8 7 6 6 5 5 4 4 36 12|| tt||13 33 12 13 14 12 15 30||tt| |6 13 14 12 15 14 16 GB12521—90||tt| |结表 最作站 depth of depth,m 27 12 16 14 7 14 17 12| |tt||16 17 24 8 14 17 16 12||tt ||21 18 混合时间,min 11 12 16 20 21|| tt||8 14 16 18 14 16 19 18||tt| |23 12 18 20 26 17 20 24 26 13 18 21 28 4 15 20 24|| tt||32 15 14 19 23 29 32 9||tt| |15 21 27 34 10 16 24 29 39 12 11 17 22 27 35 42 10|| tt||12 18 26 32 42 10 14 19||tt| |29 36 49 10 13 21 31 37 58 62 12 24 35 45 64 7 13|| tt||16 28 39 49 70 10 14 19||tt| |29 37 48 64 92 11 16 20 34 44 79 3 12 15 22 40 48|| tt||69 90 7 17 18 22 39 47||tt| |65 84 124 10 18 19 24 43 56 72 93 11 19 20 24 52 60|| hr||80||hr||105||hr|| tt||59 80 142 205 282 386 483 8||tt| |20 43 67 89 167 246 326 441 9 24 48 73 102 194 278 380 507|| tt||电影潜 水电影 symbols D F 1 * *|| tt||* * * * D G 1 *||tt| |* * * * * E 1 * * * * * * * 3.1 电影的凯去图像可来用电影水水下电影凯去或歈气水下电影电影, some programs can also use air water face pressure reduction 或oxy气水额 pressure reduction, and it may be necessary to convert from one type of pressure reduction method to another pressure reduction method. 3.2 3.3 When taking a basic pressure reduction plan, if diving The depth is the same as the depth of a certain depth. The situation of the program, should be selected more basic pressure reduction program underwater working time next, second stage or diving depth 。3.5 When using air depressurization, the stop time of each stop station is set according to the number on the table;后再取半数。后再有半数。很气击去电影电影吻水30min问是加5min间歯呼吸水水。 GB12521—90 3.6后去到9m來间(含9m)下载后气水下数Decompression. When the oxygen pressure reduction stage is implemented, the 12m stopover station can be connected to the oxygen gas in advance, the 12m stopover time is still according to the prescribed time of the air pressure reduction stage, the 9m stopover station must be connected to the oxygen pressure reduction. necessary时代么9m最了站或6m最乐站免方法最了电影应时时间的最好的最佳教,then用3min slowly rise to return to water surface。 3.7 Divemen员在水下在水下最好下载可以法小最佳在线在线3.8 When the water surface is reduced, the divers cannot continue to carry out the water in the stage when the pressure is reduced. 3.9 Diving depth within 45m (including 45m) ), 水下下载时间在水下定宜时间在水下官宜时间在水下官宜时间分在水下安家时间分内容发水水面去在最好可以可以可可去合水下的水下的水下的水水上的水上的水洗3.10 The diving depth exceeds 45m or the working time exceeds the suitable diving time limit, generally不宜安全水面化式。 遇 special circumstances need to implement water surface decompression when only oxygen gas can be used to decompress the water surface. 3m各吸oxy repeated stop for 10min,then according to the original pressure reduction scheme。 Can be within 12m(含12m) of each stopover station's stopover time more often set up in 12m and 9m stopover station。 3.11古塑*的pressure reduction scheme不宜时间安全水水外,全全家去去在可间通乐水家。GB12521—90 附较A “水水水家击去表”使用设计 (参考件)|| tt||A1 水水员在水下最作轻或中等开动最作,水水最作机水水温10℃下载、流速0.Within 5m/s, the substrate is hard, and visibility is good; divers who are healthy, feel good subjectively, regularly perform compression exercises, have certain work experience, and have no history of being susceptible to decompression sickness can use the basic decompression plan. A2 divers who are familiar with the implementation steps of surface decompression, have no history of decompression sickness, have good Eustachian tube ventilation performance, and feel good subjectively at the end of underwater work can use surface decompression. A3 If a diver accidentally rises directly from the bottom to the surface and the time spent on the surface does not exceed 5 minutes, he should dive as soon as possible to a depth 3 meters deeper than the first stop and stay for 5 minutes. At this time, the calculation of underwater working time should include this time The underwater working time of the dive, the time to rise directly to the surface, the time to delay on the surface, the time to repeat the dive and the time to stay at the depth, and select an appropriate decompression plan accordingly. If the diver has been delayed on the surface for more than 5 minutes but has no symptoms or signs of decompression sickness, he should dive to the operating depth as soon as possible and stay for 5 minutes. At this time, the method for calculating underwater working time and the principles for selecting a decompression plan are the same as above. The steps for selecting the decompression plan for A4 repeated dives are as follows: Based on a representative letter (repeated dive search symbol) of the decompression plan selected after the last dive and the surface interval time, a parameter used to retrieve the remaining nitrogen time is obtained from Table A1 representative letter (remaining nitrogen time search symbol), and then check the remaining nitrogen time that should be added to the underwater working time of repeated diving according to Table A2, and then select the decompression plan for repeated diving based on the diving depth of the repeated diving. Table AI surface interval timetable Repeated dive search symbol z o N M L K J I H 2 10 22 23 34| |tt||10 23 35 24 36 10 24 49||tt ||62 37 51 25 39 10 25 63 16 52 67 40 54 26 42 10 26| |tt||79 96 68 55 59 27 45 10||tt ||28 Remaining nitrogen time search symbol 91 115 85 103 90 60| |tt||78 29 49 10 31 116 104 124||tt ||113 99 t 32 94 10 L 162 125 149 114 138 100 125 72 95 55| |tt||79 34 59 10 36 163 150 179||tt ||167 126 154 98 123 80 107 60 89 37 66 191 225 180 213 168 202| |tt||155 188 14 124 158 108 140 90||tt ||122 67 101 226 269 214 257 203 244 189 232 159 201 141 184 123 164| |tt||102 143 270 322 258 316 245 303||tt ||233 289 217 275 202 259 185 242 165 223 144 200 328 317 404 304 92| |tt||290 378 276 260 348 340 224 312||tt ||201 289 min 41 605 405 594 393 583 379 568 363 552 349 538 341 520| |tt||313 501 290 606 720 595 720 584||tt ||720 569 720 553 720 539 720 521 720 502 720 480 720 A5 Repeated dive search symbol G||tt| |F E D c B A Repeated dive depth m||tt| |12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 Z|| tt||z 257 169 122 100 84 73 64||tt| |57 46 42 40 37 35 32 31 o 241 160 117 96 80 70 62 55|| tt||50 44 40 38 36 34 31 30||tt| |N 213 142 107 87 73 64 57 51 46 40 38 35 33 31 29 28|| tt||GB 1252190 continued table A1 remaining nitrogen time search symbol H 2 remaining nitrogen schedule table A2 G 10 40 remaining nitrogen time search symbol M 187 124 97 80 68 58 52 47 3 38| |tt||35 32 31 29 27 26 L 161||tt ||111 88 72 53 48 42 39 35 32 30 28 26 25 24 138 99 79| |tt||64 54 47 43 38 35 3 29||tt ||27 26 24 22 21 J 116 87 70 57 48 43 38 34 32 28 26| |tt||24 23 22 20 19 101 76 61||tt ||50 43 38 34 31 28 25 23 22 20 19 18 17 H 87 66 52| |tt||43 38 33 30 27 25 22 20||tt ||19 18 17 16 15 G 73 56 44 37 32 29 26 24 21 19 18| |tt||17 16 15 14 13 F 41 75||tt ||10 45 F 61 47 36 31 28 24 22 20 18 16 15 14 13 13| |tt||12 11 E 76 119 46 89 10||tt ||54 E 49 38 30 26 23 20 18 16 12 12 11 10 10 10 D| |tt||120 178 90 148 55 117 10 69||tt ||D 37 29 24 20 18 16 14 13 12 11 10 8 8 8 c 179| |tt||265 149 237 118 202 70 158 10||tt ||90 c 25 21 17 15 13 11 10 10 6 6 6 6 min B 266| |tt||455 238 425 203 392 159 348 100||tt ||169 10 130 A 456 720 426 720 393 720 349 720 170 720 131 720 10| |tt||720 min B 17 13 11 S A||tt ||7 6 S 3 3 3 2 2 2 2 2 2 凯去方法或正解加去电影。 :com Tip: This standard content only shows part of the intercepted content of the complete standard. 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