BEHR DG 2+2 User manual

192112
User's Manual
DG 2+2 / DG 6
Defattening Unit for the behrotest®CF 2+2 / CF 6
For 4 or 6 Samples, respectively

2© behr Labor-Technik GmbH
192112
Safety advice
Danger of electric shock! Make sure that no liquids get into the cable connections or the
inside of the equipment.
There are no components inside the appliance which you need to operate. Repairs to
electrical equipment must be carried out only by trained specialists. Unplug the mains
plug before opening the appliance.
Glass can break and cause injury! In working with glass components, observe all
appropriate safety precautions.
Be careful in working with corrosive substances! Follow the safety guidance in the
pertinent Safety Data Sheets.
Caution: acetone and petroleum ether are inflammable! Perform all procedures working
with organic solvents in the optional defattening unit DG 2+2 / DG 6, not in the DG 2+2
/ DG 6. Empty the waste containers regularly; define whether the contents are to be
recycled or to be disposed of.

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behrotest®DG 2+2 / DG 6
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Scope of supply
Please check the contents of the pack for
completeness and freedom from damage
immediately upon receipt.
Claims resulting from damage during transportation
which is externally apparent must be lodged
immediately with the carrier (i.e., the post/mail
service, the railway administration, the freight
organization, etc.) - see the label on the packaging.
In case of damage which is not apparent from
outside („concealed transportation damage“),
please contact the behr after-sales service
immediately upon discovery of the damage. The
same applies in the case of any other complaints.
Address:
behr Labor-Technik GmbH
Spangerstrasse 8
D-40599 Düsseldorf, Germany
Telephone: [phone]
Telefax: ([phone]
E-mail: [e-mail].
Please check the contents against the following list.
Parts list
Defattening unit
Crucible rack for docking to the DG 2+2 / DG 6
Multi-Crucible Snapperr to simultaneously take
the 4 or 6 crucibles out or insert them
4 or 6 filter crucibles, respectively,
packed separately

4 or 6 sieves to be inserted in the suction
nozzles
Hose set.
In addition, you need a collecting container each
for the acetone and petroleum ether.
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4© behr Labor-Technik GmbH
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Setting Up And Connecting
Glass can break and cause injury!
In working with glass components,
observe all appropriate safety precau-
tions.
Place the infrared crude-fibre unit DG 2+2 /
DG 6 on a flat level surface.
Hang the crucible rack on the hooks in front of
the crude-fibre unit.
Connect the waste-water hose of the crude-
fibre unit to the waste-water container
(optional).
Make sure the power switches of the devices
and, the case being, of the heating plates are
off.
Connect the infrared crude-fibre unit and, the
case being, the defattening unit to mains.
Inserting the sieves
The suction nozzles have stainless-steel sieves
laid in, to protect the pump from coarse particles in
case a frit should break. On delivery, these sieves
come packed separately.
Using tweezers, lay a sieve in each suction
nozzle.
If, later on, you want to change a sieve, take it
out of the nozzle with a pin.
Inserting the crucibles in the multi-crucible
snapper
On delivery, the filter crucibles and the heat shield
come packed separately; insert them in the device
now:
Insert the crucibles in the crucible rack.
Push the multi-crucible snapper on the
crucibles.
Inserting the crucibles in the device
Release the lock lever by pressing it down a
bit and pulling the locking grip towards yourself
with your thumb.
Let the lever come up to the end position;
release the locking grip as soon as the lever is
out of the lock position.
Insert the crucibles in the device.
Push the lock lever down until it engages.Now
the crucibles are locked.
Later on, you won't ever grasp the crucibles one by
one but insert them in the device using the multi-
crucible snapper, and get them out or transfer them
to or from the optional defattening unit.
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Insert the crucibles
in the crucible rack ...
... and press the multi-crucible
snapper on the crucibles

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192112
behrotest®DG 2+2 / DG 6
The Defattening Unit
The determination procedure of crude fibre has
some steps operating with volatile organic solvents.
Before starting the digestion itself, the sample is
treated with petroleum ether to remove fat. After the
acid digestion step it can be necessary - depending
of the nature of the sample - to remove another
fraction of fat; in this case the wet sample must be
treated with acetone first to remove water. And at
the very end, the sample is washed with acetone to
make drying easier.
These procedure steps must not be carried out in
the DG 2+2 / DG 6 digestion unit. For these steps
there is the optional defattening unit DG 2+2 / DG 6.
The defattening unit has no condensers and no IR
radiator or any other kind of heating, but, instead,
it has two separate suction pumps so you can
collect acetone and petroleum ether separately and
decide if and how they are to be recycled.
The procedure of locking and unlocking the
crucibles is the same for the optional defattening
unit as for the IR digestion unit.

6© behr Labor-Technik GmbH
192112
For samples rich in fat: Defattening
If the sample material has more than 10% fat, the
samples need to be defattened.
Caution: acetone and petroleum ether
are inflammable! Perform all proce-
dures working with organic solvents in
the optional defattening unit DG 2+2 /
DG 6, not in the DG 2+2 / DG 6.
Insert the crucibles containing the samples into
the defattening unit DG 2+2 / DG 6.
Turn all valves in "Closed" position.
Pour 30 ml petroleum ether 40 - 60 °C into each
crucible.
With the right switch, switch the petroleum-
ether suction pump on.
Now turn the first valve in "Petroleum" position
and have the first sample sucked dry.
Turn this valve back to "Closed", and have the
second and all other sample sucked dry, one
after the other, in the same way.
Repeat the defattening procedure twice more:
for each step, pour 30 ml petroleum ether in
the crucibles, turn the valves, one by one, to
"Petroleum" position, have the sample sucked
dry and close the valve again.
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behrotest®DG 2+2 / DG 6
Decalcifying
If the material contains much carbonate (more
than 50 g/kg measured as calcium carbonate), it
must be decalcified. The decalcification step can
be performed in the DG 2+2 / DG 6 as well. The
hydrochloric acid is miscible with acetone, so suck
it with the acetone pump into the acetone container.
If it has not yet been done, insert the crucibles
containing the samples in the defattening unit
DG 2+2 / DG 6.
Turn all valves in "Closed" position..
Pour 30 ml of 0.5-molar hydrochloric acid into
each crucible and let it work for one minute.
Switch the acetone suction pump on with the
left switch.
Now turn, one after another, each of the valves
into "Acetone" position and have the content
of the crucible sucked dry. Then turn the valve
back to "Closed" before opening the next one.
Repeat the procedure twice more with each
sample.
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8© behr Labor-Technik GmbH
192112
Maintenance and Care
Danger of electric shock!
Repairs to electrical equipment must
be carried out only by trained special-
ists. Unplug the mains plug before
opening the appliance.
Solvent Containers
From the defattening steps and from rinsing before
weighing there are rests of acetone and petroleum
ether 40-60°, possibly containing fat from the
samples. The acetone is mingled with water, the
petroleum ether with acetone. Regularly empty
the solvent containers, define if the residues are
to be recycled, and dispose of any residues in
accordance with regulations.
Peristaltic pumps
The pump hose is a wear-and-tear part. Check
regularly if sufficient wall thickness is left for safe
operation. Change the hose before it gets rubbed
through.
Loosen the upper knurled nut and lift the retai-
ning pin upwards out of the groove.
Pull the cover of the pump head off. You need
to tilt it a little, then pull it downwards.
Replace the tubing (complete with end nipples)
as required.
Now the pump hose and rotor are lying open before
your eyes. Check if the pump hose is still intact or if
you need to replace it.
In order to change the pump hose:
Pull the connector pieces of the old hose out of
the cut-outs of the pump housing
(see detail photo).
Pull the hoses: the discharge hose and the
hose connecting the pump to the filters, off the
connector pieces of the pump.
The new pump hose comes assembled ready-for-
use with the connector pieces.
Put the connecting hose leading to the filters to
the suction-sided connector piece of the new
pump hose.
Connect the discharge hose to the pressure-
sided connector piece.
Lay the new pump hose around the pump rotor.
Close the housing again, turn the screw
upwards again and tighten it a little.
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The flat spot
matches to
the gap in the
housing

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behrotest®DG 2+2 / DG 6
Changing the pump head
If need be, you can change the pump head too
(after taking off the pump hose).
Unscrew the two knurled nuts on the left and
right side of the pump head....
and pull off the entire pump head (the red chas-
sis) towards yourself.
The discharge hoses leading from the peristaltic
pumps need rarely ever be replaced; but check if
the hose connections are still tight.
Sealing rings: crucible mountings and funnels
The flat sealing ring in the DG 2+2 / DG 6 crucible
receptscle is the same one as in the Crude Fiber
device.
Check if any filter aid has got jammed on the
sealing ring, and if need be change it.
There is a flat sealing ring of the same kind below
each of the charging funnels that are pressed on
top of the crucibles. if this ring need be replaced
as well, force it off its seat using an appropriate
device, say,a narrow wooden spatula, and push
the new ring on its place. Make sure not to make
scratches on the funnel – remember it is made of
PTFE and quite soft.
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To change the
pump head,
undo these nuts... ... and pull the pump
head (with the red
chassis) off
Flat sealing rings
under the
charging
funnels...
...and in the
crucible
receptacles

10 © behr Labor-Technik GmbH
192112
Spare Parts and Accessories
Article Art-Nr.
behrotest®Multi-Crucible-Snapper 4fold for DG 2+2 / DG 2+2 B00645430
behrotest®Multi-Crucible-Snapper 6fold for DG 6 / DG 6 B00645422
behrotest®Sieves Set for DG 2+2 B00645428
behrotest®Sieves Set for DG 6 B00645427
Verprene hose 8 x 2 mm, per meter B00232053
Y connector, material PP, 7 - 9 mm B00661508
Suction hose, per meter B00661528
Discharge connecting hose, TPE B00227280
behrotest®crucible rack for 4 filter crucibles B00441175
behrotest®crucible rack for 6 filter crucibles B00314330
behrotest®filter crucible 30 ml for crude fibre unit, 6 pcs. B00658875
Pump hose for the peristaltic pumps for DG, with connector pieces B00668980
Pump head for the peristaltic pumps B00491177
Sensor for monitoring the maximum fill level, PP B00210222
Container 20 l, opening 49 mm inner ø B00177003
Flat sealing rings for DG 2+2 / DG 6, 10 pcs. B00521028
Technical Data
Dimensions W x H x D approx. mm
- Digestion unit DG 2+2 / DG 6
- De-fattening unit
DG 2+2
600 x 670 x 570
650 x 300 x 570
DG 6
750 x 670 x 570
800 x 300 x 570
Weight approx. kg
- De-fattening unit
21
23
Nominal voltage 230 V ~ / 50 Hz
Power consumption max. VA
- De-fattening unit 200 200
Customer Service
behr Labor-Technik GmbH
Spangerstraße 8
D-40599 Düsseldorf
Phone: [phone]
Telefax: ([phone]
eMail: [e-mail]
Internet: http://www.behr-labor.com
en: B00662088