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1108 Oxygen Combustion Vessel

P a r r   I n s t r u m e n t   C o m p a n y

6

Firing the Bomb

 

The electric current for 
firing the bomb should 
be drawn from a Parr 
2901EB Ignition Unit 
connected to an 115V 

50/60Hz grounded elec

-

trical outlet. (For 230V 

50/60Hz use a 2901EE 

Ignition Unit). Connect 
one of the lead wires 
from the calorimeter 
to the 10 cm binding 
post on the ignition unit 
and the 2nd wire to the 
middle or “common” 
terminal.

When using the bomb in a calorimeter, insert the 
421A lifting handle into the two holes in the side of 
the screw cap and lower the bomb partially into the 
calorimeter water bucket. Press the banana plugs 
on the two ignition wires firmly into the terminal 
sockets on the bomb head before the head is com-
pletely immersed in the water. After connecting 
the wires, lower the bomb into the bucket with its 
feet spanning the circular boss in the bottom of the 
bucket. Remove the lifting handle and shake off any 
drops of water back into the bucket. Be careful not to 
remove any water from the bucket with the fingers.
When using the bomb alone for analytical purposes 
it should be connected to the ignition unit as de-
scribed above and held submerged in an A387A or 
similar water bath during firing.

In all operations, check the bomb for leaks before 
firing. If any gas leakage is indicated, no matter how 
slight, 

DO NOT FIRE THE BOMB

. Instead remove it 

from the water bath; release the pressure and elimi-
nate the leak before proceeding with combustion 
test. If no leakage is indicated, adjust the water flow 
rate so that the bomb will be covered by a continu-
ous flow of cold water during the firing period, then 
stand back and press the firing button on the igni-
tion unit to fire the charge.

Caution: 

 Do not have the head, hands or any 

parts of the body directly over the bomb dur-

ing the firing period and do not go near the 

bomb for at least 20 seconds after the firing.

Filling the Bomb

The instructions below de-
scribe a manual system us-
ing the 1825 Oxygen Filling 
Connection furnished with 
other Parr apparatus.

Oxygen for the bomb can 
be drawn from a standard 
commercial oxygen tank. 
Unscrew the protective cap 
from the tank and inspect 
the threads on the valve out-
let to be sure they are clean 
and in good condition. Place 
the ball end of the connec-
tion into the outlet socket 
and draw up the union nut 
tightly with a wrench, keep-
ing the 0-55 atm gage in an 
upright position.

The pressure connection to the bomb is made with 
a slip connector on the oxygen hose which slides 
over the gas inlet fitting on the bomb head. Slide 
the connector onto the inlet valve body and push 
it down as far as it will go. If it does not slide eas-
ily, a drop of water spread around the inlet valve 
will lubricate the sealing rings. Older bombs use a 
threaded connector with a knurled coupling which 
must be turned finger tight.

Close the outlet valve on the bomb head; then open 
or “crack” the oxygen tank valve not more than 
one-quarter turn. Open the filling connection con-
trol valve slowly and watch the gage as the bomb 
pressure rises to the desired filling pressure (usually 
30 atm., but never more than 40 atm.); then close 
the control valve. Release the residual pressure in 
the filling hose by pushing downward on the lever 
attached to the relief valve. The gage should now 
return to zero. The bomb inlet check valve will close 
automatically when the oxygen supply is shut off, 
leaving the bomb filled to the highest pressure indi-
cated on the 0-55 atm. Gage. If the pressure drops 
slowly and a large amount of gas escapes when the 
pressure relief valve is opened, the check valve in 
the bomb head is not operating properly. This trou-
ble will have to be corrected before the bomb can 
be used. If too much oxygen should accidentally be 
introduced into the bomb, 

DO NOT

 proceed with the 

combustion. Detach the filling connection; exhaust 
the bomb; remove the head and reweigh the sample 
before repeating the filling operation.

2901 Ignition Unit

1825 Oxygen Filling 

Connection

Summary of Contents for 1108

Page 1: ...205M 1108 Oxygen Combustion Vessel Operating Instruction Manual...

Page 2: ...very Procedure 7 Samples and Sample Holders Particle Size and Moisture Content 8 Combustion Aids 8 Sample Pellets 8 Combustion Capsules 8 Foodstuffs and Cellulosic Materials 9 Coarse Samples 9 Corrosi...

Page 3: ...nstructions carefully in order to obtain a complete understanding of the capabilities and limitations of an 1108 Oxygen Combustion Vessel and to be well aware of the pre cautions to be observed in its...

Page 4: ...ications Parr offers the 1108CL Oxygen Combustion Vessel described below It should be noted that all instructions for the 1108 apply equally to the 1108CL as well A Chlorine Resistant Bomb The 1108CL...

Page 5: ...flame emerging from it will not impinge directly on the tip of the straight electrode Liquids in the Bomb Most combustion procedures call for a small amount of liquid to be placed in the bottom of the...

Page 6: ...ng Filling the Bomb The instructions below de scribe a manual system us ing the 1825 Oxygen Filling Connection furnished with other Parr apparatus Oxygen for the bomb can be drawn from a standard comm...

Page 7: ...stand Do not twist the head during removal Pull it straight out to avoid sticking Examine the interior of the bomb for soot or other evidence of incomplete combustion If such is found the test will h...

Page 8: ...st be added in a pellet form 2 gm pellets Never combust benzoic acid in powder form Sample Pellets One of the most useful techniques for handling powdered samples is to compress the material into a ta...

Page 9: ...h sulfur samples or with samples contain ing over 20 mg of chlorine may corrode the metal surfaces and produce a dull film on the inner walls of the bomb Materials containing appreciable amounts of ca...

Page 10: ...ent collapse of the disc when pres sure is applied Fill the bomb with oxygen to the usual charging pressure but add oxygen slowly so that the tape will not collapse into the cup Fire the bomb and comp...

Page 11: ...r condition sometimes causes spalling and the ejection of unburned fragments 5 The use of an ignition current too low to ignite the charge or too high causing the fuse to break before combustion is un...

Page 12: ...A valve needle assembly with the needle pointed up ward then adjust the parts on the needle so that the tip of the needle is flush with or slightly recessed into the bottom of the packing cup Insert t...

Page 13: ...the resistance of the metal to further attack can be improved by restoring the surface to its original highly polished condition Bombs needing repolishing or other repair work can be returned to the...

Page 14: ...Maintenance Checklist Refer to page 12 13 16 17 of the 1108 Operating Instruction Manual for assembly instructions and parts diagram 500Test Maintenance Replace the following Date Date Date Date 410A...

Page 15: ...Notes w w w p a r r i n s t c o m 15...

Page 16: ...Spacer 13 SC1932SC10 Socket Head Set Screw 14 278A3 Adapter Bushing 15 404A2 Deflector Nut 16 406A Lock Nut 17 5A10 Loop Electrode with Sleeve 18 4A10 Straight Electrode with Sleeve 19 401A Sleeve Ins...

Page 17: ...i n s t c o m 17 Parts for the 1108 Oxygen Combustion Vessel 1 3 10 30 28 9 19 A A A A 2 4 5 6 8 7 11 9 29 7 7 27 26 25 24 23 13 12 15 20 21 22 18 15 14 16 17 PROPRIETARY NEITHER THE DRAW NOR INFORMA...

Page 18: ...tion A1673E2 Kit Electric Parts for 2901EB EE 1203EEE Cord 10A 220V Cont Europe Plug 1202EEE Cord 13A 220V BS Plug 2000E Transformer 120 240 VAC 24V XB0010 1 8ID ShrinkTubing Black 34E2 Cord w 115VAC...

Page 19: ...e seat PCTFE 21VBBB Lantern ring brass 53A Oxygen gage 3 1 2 0 60 atm 112VB4AK Valve needle 124VB Union nipple brass CGA540 A140VB Toggle relief valve A150VB Valve knob 188A2 Filling connection body b...

Page 20: ...Revision 08 26 13...

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