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DATASHEET SEMICLOSED REBREATHER
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Dräger SM 1
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Date: 11 April 2005 |
Selbstmischendes
Mischgas-Schwimmtauchgerät SM1
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Database semi closed rebreathers
by: J.W. Bech
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Manufacturer |
Dräger |
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Designer |
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Model |
SM1 |
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Land of origin |
Germany |
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Design year |
1962? |
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Special Note: |
Rare rebreather |
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User group |
Military |
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Magnetic characteristics |
Non
Magnetic/ Acoustic |
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Part no: |
4220-12-140-9197 |
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Working principle
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Constant Mass Flow |
Oxygen
2 ltr/min - Air 2,2 ltr/min |
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Gas type |
Oxygen - Air |
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Oxygen is added by means
of a first stage regulator with a fixed IP of 9 bar. Resulting in a
constant oxygen flow of 2 l/min independent of the depth! |
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Air is added by means of
a depth compensated first stage regulator AND a second stage
regulator reducing the IP being 0,5 above ambient pressure. (depth
compensated). |
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The gas is mixed in a mix
tube before entering the loop. The system in supplied with two
switches who guard the pressure between the restrictors, in this way
warning the diver when the gas flow stops. |
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Intended use |
Military |
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Dimensions LxWxH
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640
x 420 x 270 mm |
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Device weight |
In
Air 25 kg in water 4,0 kg |
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Intermediate Pressure |
9
bar 02 fix/ Air Pamb+0,5 bar |
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Overpressure valve |
15
cm watercolum |
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Max depth |
40
meters |
(mtrs) |
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Used material for housing/backplate |
glass fibre |
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Pressure reducer |
Oxygen,
fixed, Air depth compensated |
Air
2 staged pressure reduction 10bar - Amb+0.5 bar |
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Connection reducer – bottles |
Oxygen
cylinder with inside thread, Air outside threat |
Aluminium
bottles 1,5 ltr max 200 bar |
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Supply pressure |
200
bar, minimum 30 bar |
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Umbilical connection |
No |
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| Color of cylinders |
Air : Gray, Oxygen: Blue |
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Manual bypass |
Yes, by pressing lever both gasses are added |
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pO2 measurement standard |
No |
Lamp guarding gasflow |
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Pressure gauge range
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0-200 bar |
Lamp fitted in mask |
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Cylinders |
2 x
1,5 liter |
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Cylinder material |
Non-magnetic |
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Cylinder thread |
G
5/8” inside and outside |
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Valve |
T-shape |
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Designed for gasmix |
Selfmixing |
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Co2 absorption cartridge
capacity |
2,1 liter |
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Co2 absorption cartridge
rechargeable |
Yes
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Co2 absorption cartridge
storagetime |
no
data |
(month/year) |
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Co2 absorption time testing
(CE) |
No |
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Connections Co2 cartridge |
The
scrubber is fixed in the rebreather housing |
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Guaranteed absorption time |
100
minutes @ 10 meter |
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Grade of absorption material |
no
data |
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Breathing bag material |
inside
rubberized |
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Inhale bag volume |
no
inhale breathing bag |
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Exhale bag volume |
10
liters fixed between exhale side and scrubber |
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Total loop Volume |
Total volume 11 liter |
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Operating temperature |
no
data |
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Magnetic signature |
low |
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Colour (s) |
green |
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Worn |
On
the back |
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FFM attached |
Yes |
(mask) |
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Mouthpiece valve |
Yes |
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Extra info: |
Low
acoustic signature |
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| Safety device |
The unit comes with a double pressure switch. In case pressure
of one of the gasses drops below a certain safety level the switch
turns on a small lamp in the divers mask. You can see the small
cable fixed on the mask. |
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Additional information: |
http://www.teknosofen.com/draeger_sm_tech.htm
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Email address owner: |
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URL owner: |
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If
you have any information to add this sheet please mail it to
jw.bech@quicknet.nl
References to source and names will always be added!
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Info found: Ake Larsson,
Tauchtechnik G. Haux, Original Manual Dräger SM1 kindly offered by
Nautiek Diving Netherlands |
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Origin:
http://www.therebreathersite.nl |
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Info: |
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The unit is equipped with an oxygen and air bottle. Both
bottles have a volume of 1,5 ltr and 200 bar working pressure.
Mixing the oxygen and air is done automatically. The mix is changing
with the depth. The carbon dioxide exhaled by the diver is removed
chemically by the scrubber. The cleaned air is mixed with the ait-oxygen
mix that is injected in the loop. The design is made in such way
that 2 ltr/min oxygen consumption of the diver is possible. The
lower fraction of oxygen pressure is restricted to 0,2 bar. When the
diver uses 0,5 ltr oxygen per minut the unit will not provide gas
with a higher partial pressure of oxygen above 2.0 bar. During a
common use of 1,3 ltr/min oxygen consumption, the partial pressure
of oxygen will be arround 1,5 bar. |
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| Example: Suppose the diver dives to 10 mtrs depth and has
filled his loop with gas. The starting percentage of the loop is 50%
of oxygen. When using 2,0 ltr/min (graphic 1) after 30 minutes the
oxygen % will drop to 20% and reaches the lower limit. At 10 mtrs
waterdepth the loop lower limit is 10%. When using 2,5 ltr/min this
lower limit is reached in 20 minutes (graphic curve 2). When using
3,0 ltr min in 10 min the lower limit is reached. |
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