Open Revolution single scrubber endurance to
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10. t I 0 50 100 Time min i 150 Figure 5 9 Scrubber endurance 5 mbar PPCO2
11. Mouth CC2 against Time I I I I I E A eee EEUU tt costs ce AM wail e ation TII mT HT i Ili Mouth O men
12. Mouth CC2 against Time ee ee aco ot uc uo od a i Endurance i l l Beers 4222 4 WAI sseae re al oe ve 6H L g Si T Q ali I alll 2 ti nl id 1 wT TR i ml il i m iii di i ini putt i 1 i pepe 1 i 0 20 40 60 80 100 120 140 160 180 Time min Figure 5 3 Mouth CO2 in the breathing loop against time Scrubber endurance 5 mbar PPCO2 146 min or 2 hour 26 min 10 mbar PPCO2 162 min or 2 hour 42 min 20mbar PPCO2 183 min or 3 hours 3 min VWAI crosses limit of 20 mbar at 175 min DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 10 of 24 Baltic Assessment Institute 5 2 Depth of 40 msw Test condition Rebreather OR rebreather Incursion 2 with PPO2 set at 1 2 atm Ambient pressure 40 msw Ambient temperature 4 1C Exhale temperature 32 4C BL humidity above 85 Tidal volume 2 litre Breathing frequency 20 min Ventilation rate 40 Ipm CO2 i
13. Mouth CO2 against Time 9 ups pp ES OPER om e TER Mouth CC g Endurance AN JN AE MI pl wal nes Thana tn nnn p anna j I i n I en A A A gt LW 5 Wet H kl x sna MID M In 2 Mul 1 il ae TL WN Gi o LL LA Neve PII RID T NN RR 1 0 20 40 60 80 100 120 140 160 180 200 Time min Figure 5 2 Scrubber endurance 5 mbar PPCO2 160 min or 2 hour 40 min 10 mbar PPCO2 178 min or 2 hour 58 min 20mbar PPCO2 198 min or 3 hours 18 min VWAI crosses limit of 20 mbar at 193 min The mass spectrometer calibration was checked online 5 1 3 Third scrubber sample
14. Figure 5 6 Scrubber endurance 5 mbar PPCO2 87 min or 1 hour 17 min 10 mbar PPCO2 114 min or 1 hour 54 min 20mbar PPCO2 152 min or 2 hours 32 min VWAI crosses limit of 20 mbar at 136 min The intervals are mass spectrometer calibration checks DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 12 of 24 Baltic Assessment Institute 5 3 Depth of 100 msw Test condition Rebreather OR rebreather Incursion 2 with PPO2 set at 1 2 atm Ambient pressure 100 msw Ambient temperature 4 1C Exhale temperature 32 4C BL humidity above 85 Tidal volume 2 litre Breathing frequency 20 min Ventilation rate 40 Ipm CO2 injection rate 1 6 Ipm STPD Make Up Gas He 5 3 1 First scrubber sample Mouth CC2 against Time gf We Hmmm NEMO i nene pane pem Mouth 002 a Endurance 5 0 00 0 l ML WA TEL l i 1 TBI II I 7 4 4 7
15. Mouth CO2 against Time 9 EP Aree EM Hou ar ae 1 Mouth CO2 l g Endurance NNNM MEN paet wal i 7 rci ER li gs ME Wii I el inion all il gt LLI 5p ese M Ba l J 3 1 i 2 il 7 id E 1 QU UBI C V j TUN a 7 7 il 1 ll i i i l i dd d j 0 gl py pli E lili E e aa EANN E EEEE EE ENNEN ne Ed 0 20 40 60 80 100 120 140 160 Time min Figure 5 5 Scrubber endurance 5 mbar PPCO2 90 min 10 mbar PPCO2 119 min or 1 hour 59 min 20mbar PPCO2 151 min or 2 hours 31 min VWAI crosses limit of 20 mbar at 135 min The interval is a mass spectrometer calibration check 5 2 3 Third scrubber sample Mouth CO2 against Time CO2 SEV
16. ili wil ern V ay s Mi i ii
17. 131 Time min Figure 6 7 VWAI CO2 at the 2 SEV point Rev A3 Page 18 of 24 DV OR ScrubberEndurance Retest SRB 101215 doc Baltic Assessment Institute Mouth CO2 Inhale CO2 Endurance WAI Mouth CO2 against Time 71 86 71 82 71 92 71 9 71 88 71 84 Time min Figure 6 8 0 5 SEV end of inhale points 6 1 4 Breath by Breath CO2 Check from 100m test The CO2 was stored breath by breath for all tests with extracts shown below Mouth CC2 against Time 10 73 10 74 10 75 10 76 10 72 Time min 10 69 10 7 10 71 10 68 Figure 6 9 CO2 sampled at the mouth showing levels with a highlight of the inhaled part of the respiratory cycle in green the end of inhale CO2 represented as the Endurance CO2 in red and the Volume Weighted Average Inspired CO2 in purple Rev A3 Page 19 of 24 DV_OR_ScrubberEndurance_Retest_SRB_101215 doc Baltic Assessment Institute Mouth CC2 against Time l EH EREET S i MR M EAE TE 10 73 10 74 10 75 10 76 10 72 Time min 10 69 10 7 10 71 10 68 Figure 6 10 Zoom into the previous plot showing the data of interest in more detail Mouth CO2 against Time Endurance WAI 144 29 144 3 144 31 144 32 144 33 144 34 144 35 144 36 144 37 14
18. ll WII ee bee aT annn i erener unia 0 50 100 150 Time min Figure 5 4 Mouth CO2 in the breathing loop against time Scrubber endurance 5 mbar PPCO2 72 min or 1 hour 12 min 10 mbar PPCO2 100 min or 1 hour 40 min 20mbar PPCO2 142 min or 2 hours 22 min VWAI reaches the limit of 20 mbar at 120 min The intervals are mass spectrometer calibration checks DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 11 of 24 Baltic Assessment Institute 5 2 2 Second scrubber sample
19. 36 min 10 mbar PPCO2 100 min or 1 hour 40 min 20mbar PPCO2 152 min or 2 hours 32 min VWAI crosses limit of 20 mbar at 138 min The intervals are mass spectrometer calibration checks DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 14 of 24 Baltic Assessment Institute 6 TEST RESULTS VWAI CO2 In accord with EN 14143 2003 the Volume Weighted Average Inspired CO2 was measured in the mouth throughout the scrubber endurance tests The results are presented below 6 1 Breath by Breath CO2 Around Breathing Loop 6 1 1 Check of all CO2 levels around the breathing loop The CO2 levels at seven points around the breathing loop is checked when the endurance test is set up An example of the results from this is shown below CC around rebreather during respiration T T T T T T 7k Respiration ner re PNE EN RU DDR Mouth Ug oe i EXVdw Bdhea 7 3 o c7 0 F4 scrBin i 5 SCRBou ir CO2 SEV Time 70ms sample Figure 6 1 Check of the CO2 flow rates example taken from the 100m test setup This shows the breathing simulator stroke Respiration Green CO2 in the mouth Blue the CO2 immediately downstream of the exhale valve Purple the Exhale Counterlung CO2 Orange the CO2 immediately upstream of the scrubber red the CO2 immediately downstream of the scrubber black the CO2 in the inha
20. Figure 5 1 Mouth CO2 in the breathing loop against time Scrubber endurance 5 mbar PPCO2 141 min or 2 hour 21 min Scrubber endurance 10 mbar PPCO2 158 min or 2 hour 38 min Scrubber endurance 20mbar PPCO2 177 min or 2 hours 57 min VWAI reaches the limit of 20 mbar at 170 min Mass spectrometer calibration was checked online To decrease the VWAI noise the gas flow into Mass Spectrometer was decreased slowly from 1 6 Ipm to 0 6 lpm during 60 110 min this is the reason for the spikes in the peak exhaled gas and the VWAI CO2 The CO2 flow rate was not affected DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 9 of 24 Baltic Assessment Institute 5 1 2 Second scrubber sample
21. n TIT 7 Endurance Q WAI A 4 WANN y 4 I 3 i TA TE i 2L uw p m NUN d di 1 Lied E cd i VU i pe illu i i T M unii o P NE L mcos me jenes tes POTE mana qoem 4 0 20 40 60 80 100 120 140 160 180 Time min Figure 5 8 Scrubber endurance 5 mbar PPCO2 35 min 10 mbar PPCO2 108 min or 1 hour 46 min 20mbar PPCO2 170 min or 2 hours 50 min VWAI crosses limit of 20 mbar at 154 min The intervals are mass spectrometer calibration checks 5 3 3 Third scrubber sample Mouth CO2 against Time i Sane nee GENE Endurance wwa C2 SEV
22. Mass spec scrubber 4 5 SEV channel lpm 6mswN2 1 7 5 then 6 8 1 8 then 0 6 2 6 8 0 6 3 6 8 0 6 40 msw 1 7 5 1 8 N2 2 7 8 1 8 3 7 5 1 8 100 msw 1 6 3 1 8 He 2 6 2 1 8 3 6 3 1 8 DV_OR_ScrubberEndurance_Retest_SRB_101215 doc Rev A3 Page 22 of 24 Baltic Assessment Institute 7 2 Tabulation of Results Table 1 SCRB endurance and VWAI CO2 level for 1 6 Ipm STPD at 4C 40 Ipm RMV Repeat 2 40m test Test End of Inhale CO2 durations min VWAI duration min 0 5kPa 1kPa 2kPa lt 2kPa 6 msw O2 1 141 158 177 170 2 160 178 198 193 3 146 162 183 175 40 msw Air 1 72 100 142 120 2 90 119 151 135 3 87 114 152 136 100 msw Heliox 1 105 136 167 161 2 35 hump 108 170 154 3 36 hump 100 152 138 7 3 Comparison with previous results The results presented here are in line with those measured by Deep Life or BAI previously Table 2 Scrubber endurance in Micropore results for 1 6 Ipm STPD at 4C 40 Ipm RMV The results presented with the EN 14143 2003 Technical File were Test End of Inhale CO2 durations min 0 5kPa 1kPa 2kPa 6 msw Air 1 165 2 155 40 msw Air 1 55 57 82 2 54 68 3 55 68 85 4 71 5 76 93 120 6 65 74 95 90 msw Trimix 1 34 2 32 44 63 The above results are essentially the same as those reported here for 6m depth no difference is expected between using air and oxygen as the make up
23. gas they have similar density conductance and permeability and in any case the PPO2 control of the rebreather increases the F O2 considerably when using air The above results are more conservative than those reported here for the 40m depth because they were carried out by sampling the gas from immediately prior to the inhale one way valve at a flow rate that in itself stimulated the turbulent bypass fault reported in the Deep Life document Fault Study CO2 Bypass 101209 pdf The Trimix results at 90m are a shorter duration than those here as the hump in the response is larger This is expected as Trimix is a denser gas DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 23 of 24 Baltic Assessment Institute The present results give a basis for claiming significantly longer scrubber endurance than are claimed in the user manual lt is understand that Deep Life have no immediate plans to increase the advised endurance 8 CONCLUSIONS The endurance results are within the narrow statistical spread of these results despite earlier results using measurement sample rates that would have created turbulent bypass of the one way valves The scrubber endurance and VWAI CO2 results show the presentation of scrubber endurance given in the user manuals for the Apocalypse and Incursion models are conservative The following durations appear to be the safe limits for the Incursion Rebreather under the EN 14143 2003 test condition
24. min Figure 6 3 VWAI CO2 at the 2 SEV point DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 16 of 24 Baltic Assessment Institute Mouth CC2 against Time 165 22 165 24 165 16 165 18 165 2 165 14 Time min Figure 6 4 0 5 SEV end of inhale points 6 1 3 Breath by Breath CO2 Check from 40m test The CO2 was stored breath by breath for all tests with extracts shown below Mouth CC2 against Time 5 82 5 83 584 585 586 5 87 5 81 5 8 5 78 5 79 Time min Figure 6 5 CO2 sampled at the mouth showing levels with a highlight of the inhaled part of the respiratory cycle in green the end of inhale CO2 represented as the Endurance CO2 in red and the Volume Weighted Average Inspired CO2 in purple All curves are shown in the full scrubber endurance curves in the previous chapter Rev A3 Page 17 of 24 DV OR ScrubberEndurance Retest SRB 101215 doc Baltic Assessment Institute Mouth CC2 against Time 581 582 58 584 585 586 587 5 8 5 79 Time min Figure 6 6 Zoom into the previous plot showing the data of interest in more detail Mouth CC2 against Time Endurance WWAI 131 01 131 02 131 08 131 04 131 05 131 06 131 07 131 08 131 09
25. 4 J 4 2 si maine i 4447 A haee BODL DTE I ET Na NE Figure 5 7 Mouth CO2 in the breathing loop against time Scrubber endurance 5 mbar PPCO2 105 min or 1 hour 45 min Scrubber endurance 10 mbar PPCO2 136 min or 2 hour 16 min Scrubber endurance 20mbar PPCO2 167 min or 2 hours 47 min VWAI reaches the limit of 20 mbar at 161 min The intervals are mass spectrometer calibration checks The hump in the scrubber endurance around 35 minutes is a known phenomena due to the time taken for the moisture balance to even out In the worst cases this can breach the CE ceiling so is given as an endurance limit in manuals As can be seen from the plot the real endurance is over 2 hours at this depth This is an extremely high performance scrubber DV_OR_ScrubberEndurance_Retest_SRB_101215 doc Rev A3 Page 13 of 24 Baltic Assessment Institute 5 3 2 Second scrubber sample
26. 4 38 Time min Figure 6 11 Extract at point where VWAI CO2 is 2 SEV Rev A3 Page 20 of 24 DV OR ScrubberEndurance Retest SRB 101215 doc Baltic Assessment Institute Mouth CC2 against Time 107 12 107 13 107 14 107 15 107 16 107 17 107 18 107 19 Time min Figure 6 12 0 5 SEV end of inhale points for scrubber 1 Mouth CC2 against Time ANIS ZOO 3522 3523 3524 3525 3526 Time min Figure 6 13 0 5 SEV end of inhale points for scrubber 2 35 21 35 2 35 19 Rev A3 Page 21 of 24 DV OR ScrubberEndurance Retest SRB 101215 doc Baltic Assessment Institute Mouth CC2 against Time of nee iM Ll Inhale CO2 J Endurance h 5 4 VWA I m oe S ee ee pe T CO2 SEV E OQ ecce Loc CREE RM ONE r ome e ee NE T 35 73 35 74 35 75 35 76 35 77 35 78 35 79 358 3581 35 82 Time min Figure 6 14 0 5 SEV end of inhale points for scrubber 3 The duration in time using the 0 5 SEV limit varies considerably because of the hump in the characteristic There is considerably less variation in the VWAI CO2 limit of 2 SEV that Deep Life prefers to use and is supported by the Open Circuit standards EN 250 and NORSOK U101 1999 7 ANALYSIS 7 1 Sample Flow rates Test Mouth CO2 amplitude SEV to achieve pre Flow in
27. Baltic Assessment Institute RETEST OF DEEP LIFE INCURSION SRB CO2 SCRUBBER ENDURANCE TO EN14143 2003 AND NORSOK U 101 DV_OR_ScrubberEndurance_Retest_SRB_101215 doc DOCUMENT Filename ORIGINATOR Oleg Zagrebelny Victor Sudakov DEPARTMENT Verification LAST UPDATED 15 Dec 2010 REVISION A3 APPROVALS Dr Bob Davidov Verification Manager Dr Vladimir Komarov 15 Dec 2010 Quality Officer Date Controlled Xx Classified Document Document DO NOT COPY Copyright 2010 Baltic Assessment Institute This is a controlled document DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 1 of 24 Baltic Assessment Institute Revision History Revision Date Description Al 9 Dec 2010 Test report issued A2 12 Dec 2010 Combined with VWAI CO2 data Internal review A3 15 Dec 2010 Approved for release DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 2 of 24 Baltic Assessment Institute Table of Contents 1 PURPOSE AND SGOP Eiaiiiccceiict cc cdiviiautieceetwtivatiacapsana TR EXE ERY Cebu ku bu du Ee C poda Pu be nnna 4 2 REQUIREMENT naue tauren ducer ented nona dae eaa a a Ed aAa aa 4 3 EQUIPMENT USED rna dan rnb s a nea rada eaa ia ri aa eda a E XR da 5 4A METHOD 6 5 TEST RESULTS ENDURANCE iissisciciiicicietestaesedevcisnedeisassederedvandannieandontaecduannedouns 9 SI Depth OF OPE 9 2 L T First scrubber sam
28. breather limit is a VWAI 2 SEV limit then there is no significant difference with depth the rebreather has a 140min to 180min duration As the final part of the dive is carried out near 6m depth then the figure quoted by Deep Life that the diver does not exceed a 2 hour 45 minute duration for any dive using the VWAI 296 SEV limit appears to be reinforced by these test results DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 24 of 24
29. configurations 4 Fault Study CO2 Bypass 101209 pdf providing analysis of a fault mode that may affect the apparent scrubber endurance 2 REQUIREMENT The CE EN14143 2003 and the comparable NORSOK U 101 test specify the following test conditions 1 Water temperature is 44 1C 2 Carbon dioxide injection rate is 1 6 lom STPD 3 Breathing simulator rate is 40 lpm 4 Breathing frequency is 20 bpm Scrubber endurance must be measured with lt 150ms accuracy and resolution as e End of inhale CO2 level in the mouth of 5mbar 0 5 SEV for EN 14143 2003 e End of inhale CO2 in the mouth of 10mbar 1 SEV also EN 14143 2003 e A further limit that VWAI CO2 does not exceed 20mbar 2 SEV EN 14143 and NORSOK U101 The depths measured are the worst case profile to e 6m using oxygen as the make up gas e 40m using air as the make up gas e 100m using heliox as the make up gas The word profile is considered by Deep Life to be unsafe in that divers may not study the profile where this involves a specific decompression schedule Deep Life s definition of the worst case profile is therefore constant depth With the increase in case diving and use of rebreathers for bottom phases of a dive this worst case may be the actual worst case dived Three scrubbers are measured at each depth EN14143 2003 requires that the Volume Weighted Inspired CO2 VWAI CO2 is measured during the endurance test BAI store all VWAI CO2 for the entire test breath b
30. essesanssestcecscossoansseseseteanseooees 22 7 2 Tabulation of Results eine dus vsbesuscsseceusunbvcusedeenstatecbsoustasucusnaasesenstdesssuausersaus ecesbsviesonetpes 23 7 3 Comparison with previous results cortes eteotks arse pner bas rori urn obe Lis t rk otio pus eub A e Yensos ise id san 23 8 CONCLUSIONS us inician raea a a a nk ih Cento n x ean dan x Din 24 DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 3 of 24 Baltic Assessment Institute 1 PURPOSE AND SCOPE The purpose and scope of this report is to provide a retest of CO2 scrubber endurance for compliance with EN 14143 2003 for the Deep Life OR Incursion model as previous data on that rebreather had performed the test with the oxygen control switched off to avoid any risk of interfering with the measurement This is a single scrubber configuration that has the same scrubber as the Apocalypse model This document is one in a series that assesses the CO2 scrubber endurance on the Deep Life Open Revolution rebreathers These include 1 Scrubber endurance data provided in the User Manual supported by data in the Scrubber Endurance directory of the PPE Directive Technical File 2 DV OR Scrubber Endurance 081124 doc providing data for the single scrubber configurations with particular regard to the sensitivity to low temperatures 1C to 5C diver attitude and gaps in scrubber use 3 DV OR ScrubberEndurance DRB 081202 pdf providing data on the dual scrubber
31. le counterlung light blue and the CO2 immediately upstream of the inhale one way valve dark green This checks the entire fixture and in particular the CO2 upstream of the scrubber shows the correct fraction of CO2 is being injected it is 4 46 SEV at BTPD from 4 of tidal gas at SPTD 273 32 273 DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 15 of 24 Baltic Assessment Institute 6 1 2 Breath by Breath Check from 6m test The CO2 was stored breath by breath for all tests with extracts shown below Mouth CC2 against Time CO2 SEV Figure 6 2 CO2 sampled at the mouth showing levels with a highlight of the inhaled part of the respiratory cycle in green the end of inhale CO2 represented as the Endurance CO2 in red and the Volume Weighted Average Inspired CO2 in purple All curves are shown in the full scrubber endurance curves in the previous chapter Mouth CC2 against Time eR L Mouth OOR EM Inhale CO2 A e a NE imer ri Ln wal pog l l l T T err 3 m ta 4 En o 2 eg i E l i i ha Ros IU EE puse EE EEA EE adus l 4 a 331 E 2 o Moped esee MEA or a ee 8 3 ZEN aL i NEN PEE EE PENNE f Od CHECA pex L Bio LU d Ende 1 191 16 191 17 191 18 191 19 191 2 191 21 191 22 191 23 191 24 Time
32. ng frequency 20 min Ventilation rate 40 Ipm CO2 injection rate 1 6 lom STPD Make Up Gas O2 5 1 1 First scrubber sample Mouth CC2 against Time to E woaoce r4 i Endurance i i i i T 9 wA qe ape MM pen 777 ad i i i i i i a anl Il Bere ee eas jose ES MM Br Fr ud lis 5 lanas AUTO i im SAAT e Me ERE it TUM I Q i i TX x tiene e ate eee Heat t 2 TT MII 4 TEILE wm IT 7 Mi Tm Time min
33. njection rate 1 6 lom STPD Make Up Gas N2 5 2 1 First scrubber sample Mouth CC2 against Time Moth O2 adl 3 Endurance we a TUNI VWAI aud E II 8 KNEE E LL LIED A BI OW i iy MM IAM TI TNT IM TI AOT I ANII Daa oar i 6 ARI T i ADU HAV MATA II MM WAIN I i TIRE T TURA A TI 3 LOTO TRITT I ME ME WI li oA LED LA TL
34. pectrometer 15 ml min Chamber drain 1 6 l min A V valve at STP e ii te 88 Differential Pressure Pressure N wt 2S w r t suprasternal notch tranducer St 2 AN y amp s 6 Dif E o Sx Pressure Water temperature ALV REBREATHER MOUNTED sensor ON MANNEQUIN BREATHING SIMULATOR 1 6 l min STP 0 8 mm I D Heater with gas temperature sensor Gas temperature 4 sensor CO2 at STP 0C injection point with selectable deadspace w r t mouthpiece Humidity sensor ES temperature sensor Solenoid valve for injecting Counterlung Suprasternal notch Rebreather Scrubber Analogue pressure gauges for safety purposes only PC2 Datalogging 1 stage regulator Oxygen Water of 4 1C Make up gas O2 N2 or He Refrigeration System 2 4KW oo0o000000000000000 gt OOOo0O0O0000000000000 calibration pulses 800 mm CHAMBER Counterlung Figure 4 3 Scrubber endurance test fixture Rev A3 Page 8 of 24 DV OR ScrubberEndurance Retest SRB 101215 doc Baltic Assessment Institute 5 TEST RESULTS ENDURANCE 5 1 Depth of 6 msw Test condition Rebreather OR rebreather Incursion 2 with PPO2 set at 1 2 atm Ambient pressure 6 msw Ambient temperature 4 1C Exhale temperature 32 4C BL humidity above 85 Tidal volume 2 litre Breathi
35. ple irisse ret te teens et e Le He ase caves Pte ee cta 9 3 12 Second scr bber Sample et Deeper eedem eie tee re eee hovel deste E 10 5 L3 Third scrubber sample reete reti Feng ca ae Dee e RE eta epo ede canne 10 S22 De pth0f I d R 11 3 21 b rstscr bber sample 5 Ite ettet ite rte Pee E e EPIS CE tiere en eee dere ee aS 11 23 22 Second scrubber sample sr ee etse tee e a EE ee HER EORR Re E suey 12 3 2 3 Third ser bber sample RN d RR 12 53 _ Depthof 100 MSW c 13 5 3 1 First scrubber sample i ee Re Ute e Ee E ae eae e edens 13 3 3 2 Second scr bber sample oo ede Rte ga d ge a ends 14 5 323 Third scrubber sample eret eet creen eer nete itera 14 6 TEST RESULTS VWAI CQ2 iiiasisnskexssinieuxvus ecce gau ua sinn UE REP aane dadana p ianiai aasid iaiia 15 6 1 Breath by Breath CO2 Around Breathing Loop ecce eee e ee eee eee eene eee en eee to seta aee t eaae 15 6 1 1 Check of all CO2 levels around the breathing loop eeeeeeeeeeneeeen 15 6 1 2 Breath by Breath Check from 6m test eene nennen nennen nennen 16 6 1 3 Breath by Breath CO2 Check from 40m test sees 17 6 1 4 Breath by Breath CO2 Check from 100m test esee 19 T ANALYSIS inneni eneen nara taeae edna ETA CE PASVRY NSUS UR FS airaa eienaar aaran 22 T gt Sam ple Flow Patsy scesscisccsserssssencsessevsecssevssnsdsensseseosseeevssnascoass vosesssedbsesc
36. s of 40 Ipm RMV 4C water 1 6 lom of CO2 injection at STPD e 6m O2or Air 40 minutes duration to a 0 5 SEV limit 3 hour duration to the VWAI 296 SEV limit e 40m Air 70 minutes duration to a 0 596 SEV limit 140 minute duration to the VWAI 2 SEV limit e 100m Heliox 30 minutes duration to a 0 5 SEV limit 150 minute duration to the VWAI 2 SEV limit At 90m using Trimix the limits indicated from the previous tests are considerably more conservative and these should remain For dive profiles Deep Life recommend that durations at the various depths are used For example a scrubber endurance quoted for a 40m dive profile typically consists of just 20 minutes at 40 at the end of which some breakthrough can be seen then the depth is reduced to 9m or even less and the rest of the test is at that depth Deep Life make the point that divers read that a 90 minute duration quoted on a popular rebreather for a 40m profile as being a 90 minute duration but in fact the actual duration at that depth to the CE limit is more likely 30 minutes at that constant depth By quoting constant depth the diver can see the endurance at a constant 40m then if decompression is at 6m the proportion of the endurance remaining can be determined from the constant depth figure for 6m In the case of this apparatus there is a significant difference with depth at the 0 5 SEV limit but using the Open Circuit VWAI limit of 2 SEV also the NORSOK U101 re
37. ses are computer controlled and logged The breathing simulator was calibrated with both NEDU and CE test orifices prior to each test series and following the last test CO2 is injected as a pure gas into the breathing simulator Simulator dead space has no affect whatsoever on the inhaled CO2 waveform it affects the exhaled CO2 waveform but not the average after the exhale one way valve Dead space settings of 150ml and 800ml are used routinely the later allows gas to be extracted from the mouth for sample purposes without changing the VWAI CO2 or End of Inhale CO2 because it inserts a time lag to the exhale cycle during which the mouth CO2 remains at the End of Inhale level The chamber temperature is kept at 4C by a 2 4KW industrial cooler providing refrigerated liquid around the chamber For tests of more than 3 hours water is exchanged from the top of the chamber to keep the test at 4C using bleeding and a hydrostatic pressure test pump The requirement of EN 14143 2003 is to measure CO2 in the mouth This is achieved by taking a 1 8 lom feed from the mouth at the interface between the mouthpiece and breathing simulator to a mass spectrometer which records the breath by breath gas fractions with resolution of 70ms for all gases Where noise is observed at this bleed rate such as for shallow tests the bleed rate is reduced until the noise is removed the bleed rate is not less than 0 6 lpm The rate of CO2 injection is critical to
38. st commencing The procedures for the setup and execution of the scrubber endurance test is controlled through the BAI Test Manual DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 6 of 24 Baltic Assessment Institute Pressure Temperature phase diagram for CO2 oe Cao ere EPEE Bex boe uf d i ee t E w i D l o I A I ee ee ee hae ne f formula table data 4 20 25 Temperature C Figure 4 1 Gas liquid phase diagram of CO2 detail This relationship enables the mass flow of the CO2 to be compensated for the temperature of the gas by measuring the pressure of the supply cylinder 1000 CO solid Sublimation point 10 8 5 C at 1 atm Critical point Pressure atm Triple point D 1 56 6 C at 5 11 atm 0 001 140 120 100 60 60 40 20 0 20 40 60 0 100 Temperature C Figure 4 2 Gas liquid phase diagram of CO2 DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 7 of 24 Baltic Assessment Institute CO2 cylinders os Manual pressure regulator OPERA Ga Flowmeter Mass Flow Controller PC3 long time data capturing 2 Mass Flow meter LPT port Position sensor Gas temperature sensor 9 D Digital gauge with valid calibration a k o PC 1 Z with Real Time 2 controller Mass x S
39. the test The injection rate is checked using a variable area sight gauge prior to the test then monitored throughout the test by e Mass Flow Controller reading the mass flow controller having been calibrated using CO2 at NTPD Temperature compensation is applied manually as will be described e Mass Flow Meter reading this being in series with the Mass Flow Controller e Mass Spectrometer reading of the average CO2 immediately before the scrubber to ensure this is at least 4 SEV at all times e Continuous molecular weight monitoring Precision scales are used to weigh the CO2 cylinder a twin 20 litre twin set 40 litres of gas This is an absolute reference that is used to monitor the Mass Flow Controller compensation to ensure it is always within its calibration The pressure of the CO2 is monitored to determine the temperature of the CO2 being delivered to the Mass Flow Meter and Controller The maximum pressure of CO2 against temperature is shown in Figure 4 1 This plot is derived from the CO2 pressure temperature phase diagram shown in Figure 4 2 The low gas temperature means that the Mass Flow Controller is set to 1 75 Ipm of CO2 flow the exact number depends on the gas temperature at the time of the test but is never less than 1 72 lpm This is more than the 1 6lpm stipulated in the standards because the standards use STPD and the MFCs are calibrated with NTPD A Checklist is used for each scrubber test prior to the te
40. y breath DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 4 of 24 Baltic Assessment Institute 3 EQUIPMENT USED The test equipment used is listed below DL Human Respiratory Emulator DL 001 Calibrated prior to Breathing simulator each use DL Rev C2 Differential pressure sensor Druck 2393261 Calibrated prior to LPM9381 each use Highly precise digital manometer Keller 002333 16 July 2011 LEX1 High pressure sensor Calibrated prior to ME 705 HEUS each use National Instruments Against TTi 1906 pale a HA4375847 Serial Number PCI 6014 111474 Prior to test Power supply GPR 1850 033624 N A Scales VSP 60 10 5 7012 23 11 2011 Mass spectrometer Uses certified span Amis 2000 with SN 0911243 gases to calibrate at suitable span gases each test Deep Life 800 mm chamber with Next hydrostatic Sept CH03 environmental 2014 control rotateable Hot wire anemometer Q440965 Dec 2011 Note 1 the Breathing Simulator is a complex measurement system and contains additional sensors not listed in the table above This information is provided at Breathing Simulator Calibration report Ca Breathing Simulator Assessment 090707 pdf Remainder of page blank DV OR ScrubberEndurance Retest SRB 101215 doc Rev A3 Page 5 of 24 Baltic Assessment Institute 4 METHOD The test fixture used for scrubber endurance tests is shown in Figure 4 3 All operations of the test fixture other than connecting ga
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