LABBOX KJD20 User manual

KJD20 Kjeldahl Automatic Distiller
Please read the User Manual carefully before use and follow all operating and safety instructions!
user manual
english

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User Manual
KJD20 Kjeldahl Automatic Distiller
Important notice
This instrument is designed for laboratory usage only. Please read this manual carefully before installing or operating this
equipment. The instrument shall not be modified in any way. Any modification will void the warranty and may result in
potential hazard. We are not responsible for any injury or damage caused by any non-intended purposes and modifying
the instrument without authorization.
Service
In order to guarantee this equipment Works safely and efficiently, it must have a regular maintenance. In case of any
faults, do not try to repair it yourself. If help is needed, you can always contact your dealer or Labbox via
www.labbox.com
Please provide the customer care representative with the following information:
• Serial number
• Description of problem
• Your contact information
Warranty
This instrument is warranted to be free from defects in materials and workmanship under normal use and service, for a
period of 12 months from the date of invoice. The warranty is extended only to the original purchaser. It shall not apply to
any product or parts which have been damaged on account of improper installation, improper connections, misuse,
accident or abnormal conditions of operation.
For claim under the warranty please contact your supplier.

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I. Safety
1. Overview
This operating manual is prepared for the laboratory instrument operators. Please read this manual
carefully before using the instrument and conduct the operation according to the manual. Personnel
who are not familiar with the instrument operation or safety information shall not operate the
instrument.
This instrument adopts the current most advanced technology for design and manufacturing. But the
improper use of this instrument will cause a potential safety hazard.
The instrument manufacturer has made the assessment on the possible hazard:
-Inexperienced personnel operating the instrument
-Failure to operate the instrument according to the normal regulations
-The operators of this instrument shall know all the below mentioned warnings.
2. Safety
Warning: This instrument is only used for laboratory. If the instrument is damaged due to the
failure of conducting the operation according to the manual during the use, the manufacturer refuses to
bear all consequences.
Warning: If the failure of using the instrument properly or conducting the operation according
to the operating manual causes any consequences, the company will not bear the safety problem of
instrument use.
Warning: The failure of operating the instrument as required by this manual will weaken the
safety performance of the instrument.
Warning: Please conduct the treatment of various solutions used in the test according to the laboratory
safety regulations. Operators shall wear the rubber gloves, lab coats and goggles.
Warning: Oral intake of boric acid will cause acute poisoning, which is mainly embodied in
gastrointestinal symptoms, nausea, emesis, abdominal pain, diarrhea, etc., and then dehydration,
shock, coma or acute renal failure, or high fever, liver and kidney damage, convulsions and even
cause death if serious. It is easily absorbed by the damaged skin and causes poisoning. Chronic
poisoning long-term absorption of small amount of boric acid in gastrointestinal tract or skin will
lead to mild digestive tract symptoms, dermatitis, baldness and liver and kidney damage.
Warning: Sodium hydroxide has causes irritation and shows high corrosivity. The powder or
smog will irritate the eyes and respiratory tract and corrode nasal septum. Direct contact of skin or
eyes with sodium hydroxide may cause burns, and accidental take-in can cause gastrointestinal
burns, mucosal erosion, bleeding and shock.
Warning: Sulfuric acid (95-98 %) has intense irritation and corrosive effect upon the skin,
mucosa, and other organs. Vapor or mist may cause conjunctivitis, conjunctival edema, and corneal
opacity, and consequently blindness; it may cause respiratory irritation, and may cause dyspnea
and pulmonary edema in severe cases. High concentration may cause the laryngospasm or glottic
edema, and finally death by suffocation. Oral take-in may cause digestive tract burns and thus
elcosis. It may cause gastric perforation, peritonitis, renal damage, shock, etc. in severe cases.
Warning: The temperature of the digestive tract will reach 100 ℃during the experiment.
After completing the distillation, take the testing tube out with test tube holder for avoiding scald.

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Warning: Please use the power line provided by manufacturer. Other power lines will affect
the safety performance of the instrument.
Warning: This instrument is equipped with the special grounding power plug for preventing
electric shock. Please use the grounding receptacle.
Warning: Electric shock hazard. Only professional and qualified persons are permitted to
open the machine cover and the panel.
Warning: The instrument shall not be used under an environment with potential explosion risk.
Warning: Paraffin or reagents containing paraffin can damage the equipment.
Warning: The power switch in the lower right side of the instrument can be reached easily at
any time, making sure that the power can be turned off at any time.
Notes: Do not touch or open the protective door during the instrument operation.
Notes: Make sure that the liquid solution does not contact the power line and electric parts
inside the instrument.
Notes: Stop using the instrument in the case of failure, and timely contact the nearby
manufacturer service center.
Notes: This instrument shall be repaired by authorized personnel. Manufacturer recommends
using the original spare parts. If the spare parts from other sources are used, the quality guarantee
will be invalid.
Notes: The instrument is designed and tested according to EU standard (CE). To guarantee
the continuous conformance to the standard, the instrument can only be connected with equipment
meeting CE requirements.
Notes: The unboxing, assembly and installation of the instrument shall be completed by
personnel authorized by manufacturer.
Notes: Please make sure that the water, electricity, and gas sources of the instrument are turned off after
the experiment is completed. (Please operate according to the actual situation!)

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3. Guidance for Waste Disposal
It is not allowed to discard the electronic devices together with non-classified general waste. Improper
disposal will produce damage to the environment and human health. Please refer to the local waste
disposal regulations for collection and disposal of the equipment.
4. Quality Guarantee Policy
The quality guarantee is generally specified in the purchasing order or contract, and is only
applicable to:
· The user shall abide by all written explanations and documents of manufacturer.
· The equipment shall be installed, maintained, adjusted and calibrated according to the methods
described and recommended in the documents.
· The equipment is not used for other purposes beyond those specified by manufacturer.
· The equipment is not refitted or repaired with spare parts which are not from the manufacturer and
is not repaired by personnel authorized by the manufacturer.
· Only use the accessories and consumables provided by manufacturer from the source recommended
by manufacturer.
· The equipment can't be operated according to the way which is inconsistent with the ordinary
practice.
· Only software authorized by manufacturer can be installed in the PC of the equipment.
· Use the external PC meeting the requirements recommended by manufacturer.
· The equipment shall conduct the correct maintenance according to the requirements recommended by
manufacturer.
· The equipment contains some quick-wear parts, and these spare parts can be inquired in the user's
manual and user's guide.
· The quality guarantee responsibility of quick-wear parts is only limited to the damage caused by the
material defects or production problem.
II. Introduction
1. Application
The Kjeldahl method is the classical method of nitrogen and protein determination. Currently, Kjeldahl Distillation
Unit plays an important role in determining the nitrogen and protein contents of soil, food, agricultural products
etc. Kjeldahl Distillation Unit can be widely used in areas of food processing, feeding stuff production, tobacco,
farming, soil fertilizer, environment monitoring, agriculture, scientific research, education, and quality control and
so on, performing either the nitrogen and protein analysis to macro and semi-micro samples, or tests of
ammonium salt and volatile fatty acid/alkali etc.
There are three processes including digestion, distillation and titration when Kjeldahl method is adopted to test
samples. The distillation is the main determining process used in Kjeldahl Distillation Unit, which is an automatic
distillation system designed according to the classical Kjeldahl method. This Kjeldahl Distillation Unit provides the
lab staff with a great convenience in measuring the content of nitrogen and protein, owning features such as high
reliability, uncompromised safety, hassle-free operation and time and energy-saving performance etc. The user-
friendly interface written in English is easy to operate and can display the sufficient information, making users
easily understand how to handle the Kjeldahl Distillation Unit.

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++⎯⎯⎯⎯⎯⎯ →⎯+ 3242
steametemperatur-high
424 222)( NHOHSONaNaOHSONH
OHOBNHBOHNH 27424333 5)(42 +=+
2. Theory
According to the Kjeldahl theory, there are three processes including digestion, distillation and titration
in the test. The Kjeldahl Distillation Unit is able to execute the distillation process automatically.
The chemical reactions listed below occur after a sample has been completely digested.
[1]
[2]
Via the condensing pipe, the ammonia gas and steam released during the reaction are condensed and
collected into the receiving flask where the boric acid (with mixed indicator) is added.
III. Specifications
1. Technical Specifications
a. Measurable amount of the sample: solid ≤ 5 g; liquid ≤ 20 mL
b. Measurement range: 0.1 mg～240 mg of nitrogen
c. Time for measurement: 3~6 min
d. Recovery rate: ≥ 99.5 %
e. Relative Standard Deviation (RSD): ≤ 0.5 %
2. Working Conditions
a. Rated power: 1300W
b. Input voltage: AC 220 ±10% V (50/60±1) Hz; reliable ground wire is needed.
c. Cooling water pressure: > 0.15 MPa
d. Cooling water temperature: ≤ 20 ℃
e. Temperature of environment: 10 ℃ ～35 ℃
Working Humidity: 35 ℃and max. relative humidity 67 %; 31 ℃and max. relative humidity 80 %.

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IV. Names of Kjeldahl Distillation Unit Parts
The Kjeldahl Distillation Unit is a special system, which can automatically distill the completely digested
samples and show the workflow in real time mode. The system mainly consists of a microcontroller,
steam generator, distillation system and an automated reagent dispensing system. The exterior
structure is shown in the following diagram:
Fig. 1. Front view
1. LCD 2. Connector for liquid-collecting tube
3. Waste receiving tank 4. Protection door 5. Digestion tube
V. Installation Instruction
1. Pre-installation Check
After the Kjeldahl Distillation Unit is unpacked, check the whole instrument and all marked spare parts
according to the attached packing list and check whether they are damaged or not. If something is
damaged, please contact the manufacturer timely. (Please keep the damaged parts.)
2. Installation Conditions:
The Kjeldahl Distillation Unit should be installed in neither excessively hot, cold or humid places nor
places with excessive sunlight exposure. Commonly, the room temperature should be maintained
between 10 ℃～35 ℃. The instrument should be installed on a clear, level and stable platform, which
should be close to the water source and draining sink. The distance from the instrument to the water
valve, draining sink and power supply should be shorter than one meter to ensure the convenient
operation. The distance between the instrument and the wall or other devices should be at least 40 cm.
For your safety, do not store anything on top of the instrument or any container, chemical agent or
devices etc. behind the instrument.
The pressure and temperature of the water supply should meet the certain requirement, and the water
should be clear and free of impurities (see Chapter 2 Item 2 for details). The draining sink should be
lower than the discharge outlet of Kjeldahl Distillation Unit to ensure the good water-discharging
performance.

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The power supply should meet the specified requirement, which must have ground wire, independent
power switch and fuse protection to guarantee the safety of operators.
The Kjeldahl Distillation Unit should be far away from any big-scale electric equipment, and its
working environment should be free of vibration and electromagnetic interference, in which there is no
corrosive substances.
3. Installation Procedures:
View of Left Side (Fig. 2):
Fig. 2. View of left side
6. Cooling water intake 7. Water discharge outlet (connect to drainage sink) The water
intake (6 )is commonly connected to the faucet of tap water. The water discharge outlet (7)
is connected to drainage sink and must make sure that the discharging performance is good.
View of Right Side (Fig. 3):
Fig. 3. View of right side
8. Ventilation hole for alkali bottle 9. Ventilation hole for boric acid bottle 10. Ventilation
hole for distilled water bottle 11. Intake of alkali solution 12. Intake of boric acid
13. Intake of distilled water
The ventilation hole for alkali bottle (8) is connected to the air tube of alkali bottle.
The ventilation hole for boric acid bottle (9) is connected to the air tube of boric acid bottle.
The ventilation hole for of distilled water bottle (10) is connected to the air tube of distilled water
bottle.
The intake of alkali solution (11) is connected to the delivery tube of alkali solution bottle.
The intake of boric acid solution (12) is connected to the delivery tube of boric acid solution bottle.
The intake of distilled water (13) is connected to the delivery tube of distilled water bottle.

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Back View (Fig. 4):
Fig. 4. Back view
14. Power switch 15. Power cord socket 16. Fuse device
The power cord can be plugged into the power cord socket (15). The blown fuse can be replaced in
the fuse device (16) (There is a spare fuse in the fuse socket). Slide the power switch (14) to turn on the
instrument.
VI. Sample Preparation
1.Solution
Copper sulfate (CuSO4·5H2O )
Potassium sulphate (K2SO4)
Vitriol (1.8419g/L )
2. Procedure
Weight 0.2-2 g solid sample or 2-5 g semisolid or take 10-20 mL liquid sample (around 30-40 mg
Nitrogen), then put it into a digestion tube, adding a catalyzer tablet and heating the sample in the
Kjeldahl Digestor, when the substance is carbonized completely and there is no foam, heat the liquid
to low boiling and keep it, until liquid turns to clear and blue-green. Then heat 0.5-1 h continually.
When the digestion is finished, cool it. At the same time, do the blank test.
VII. Operation Instruction
1. Preparation of the Chemical Reagent
(1) Add distilled water into the distilled water bottle (with a blue label marked with “H2O”) and then
tighten the bottle cap.
(2) Prepare the sodium hydroxide solution (NaOH ) (concentration: 30 ％～40 %), add it into the
alkali solution bottle (with a yellow label marked with “NaOH”) and then screw the bottle cap firmly.
(Concentration of 35 % is recommended because the solution with this concentration is not subject to
the crystallization and does not cause the pipe clogging when the room temperature fluctuates.)
(3) According to the need of experiment, use Bromocresol Green/Methyl Red Indicator.
(4) Prepare the boric acid (H3BO3) with a concentration of 2 %, and then add Bromocresol Green/Methyl Red
Indicator at the proportion of 100:1. After they are well mixed, pour the solution into the boric acid bottle (with
a red label marked with “H3BO3”), and screw the bottle cap tightly.

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2. Operation Panel:
Fig. 5
1. Easy -touch keypad and keys with protective film.
2. Environmentally friendly LCD with blue background light.
3. Heating indicator, which can be on or off according to the distillation process.
4. Warning indicator, which is on when there is any malfunction in the system or any necessary factor is
missed in the distillation stage. Attention: in the warning condition, warning words are showed on the
screen and the warning sound goes off at the same time.
5. Power light, which can indicate the state of power supply and is on when the instrument is turned on.
3. Functions of the Keys:
Number key: For the input of parameters.
【Stop】key: Press the key in case of any need to stop during heating or distillation, the experiment
will stop and the instrument will return to the initial interface.
【Auto】key: Press the key to Enter the interface for automatic test parameter modification when the
instrument is under the initial interface or test selection interface.
【Manual】key: Press the key to Enter the interface for manual test when the Kjeldahl Distillation Unit
is under the initial interface or test selection interface. The instrument will get started and enter the
main interface, including test, maintenance and help.
【Enter】key: Press the key for next interface.
【Back】key: Press the key for the previous interface.
【Up】,【Down】,【Left】,【Right】key: Press these keys for input of parameter or option selection.
Attention: Check the solution in the jar for boric acid, alkali liquor and distilled water first to see
whether they are sufficient for use prior to starting the Kjeldahl Distillation Unit. Add the
formulated solution in time if they are not sufficient, otherwise, it could cause inexact distillation
results or system malfunctions.

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4. Operation Modes For the Kjeldahl Distillation Unit After Start-up
The Kjeldahl Distillation Unit will enter the initial interface shown in Fig. 1 after start-up:
Fig. 1
The initial interface provides three modes: test, maintenance and help. You may use 【Left】and
【Right】key to target “test” button and press 【OK】key for the test mode. See Fig. 2
Fig. 2
You may use 【Left】and 【Right】key to target the desired operation setting and press 【OK】
key for next interface. Press 【Auto】key for automatic test parameter interface, or press 【Manual】
key for manual test interface.

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I Test
1 Automatic Test
The Kjeldahl Distillation Unit Enters automatic test parameter interface shown in Fig. 3
Fig. 3
Press 【Up】,【Down 】,【Left 】,【Right】keys to target the parameter, and press
【Number】key for modification. Press 【OK】key for safety notes shown in Fig. 4
after input of parameters and press 【Back】key for the previous interface.
Fig. 4
Press 【OK】key for the test. The test will be carried out automatically by the system, and
adding boric acid, adding dilution water, adding alkali, distillation and drip washing shall
be performed in sequence. The small icon will turn colorful and revolve during operation and
turn grey in idle condition. The icon in idle condition, such as adding boric acid, is shown in
Fig 5.
Fig. 5

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The icon during operation is shown in Fig. 6.
Fig. 6
You may press 【Stop】key to end the experiment. The first interface on completion of the
test is shown in Fig. 7.
Fig. 7
2 Manual test
The system will offer safety notes first, as shown in Fig. 8, when you select the manual test
interface.
Fig. 8
Press 【OK】key for manual test interface. Each option may be selected by【Up】,【Down】
keys. Take adding boric acid for example, as shown in Fig. 9, press 【Down】key for
dilution water interface and press 【Up】key for drip washing interface.

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Fig. 9
Input the volume of boric acid to be added with 【Number】key and press 【OK】key for
adding, as shown in Fig. 10.
Fig. 10
You may press 【Stop】key to stop adding during the experiment.
3 Maintenance
Maintenance includes flushing of alkali piping, liquid adding for calibration, function
commissioning, safety setting and flushing of alkali piping. The alkali piping shall be flushed
regularly in strict accordance with the instructions, as shown in Fig. 11.
Fig. 11
Wash the alkali jar clean, add the distilled water and place the empty digestion duct in
position. When everything is ready, press 【OK】key for the next step, as shown in Fig. 12.

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Fig. 12
Press 【OK】key for flushing of alkali piping, otherwise press 【Back】key for exit. The interface for
alkali piping flushing is shown in Fig.13, and it will Back to maintenance interface after flushing.
Fig. 13
Liquid adding for calibration
Liquid adding for calibration includes calibration by dilution water, alkali solution, boric acid solution
or drip washing water, as shown in Fig. 14.
Fig. 14
The calibration by dilution water is shown in Fig. 15. Calibration by other solutions is operated in a
similar way.

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Fig. 15
The instructions on the interface shall be observed strictly prior to calibration. When everything is
ready, press 【OK】key and the Kjeldahl Distillation Unit starts adding liquid to the digestion duct
through the dilution water valve. Liquid adding will end with a “tick” sound and the dialogue box will
appear in lower part of the interface, as shown in Fig.16. Input the volume of the liquid received in
the “Please enter volume” section and press 【OK】key for end of calibration. Or press 【Return】
key to quit calibration.
Fig. 16
Press 【OK】key, and a small interface will appear, as shown in Fig. 17. You may verify the accuracy
of the solution calibration by pressing 【OK 】key for adding a particular amount of solution,
otherwise press 【Return】key to quit calibration.
Fig. 17
Notes: Please discard the liquid received in the first calibration for accuracy. The volume
of liquid received may be measured several times and input the average result to the
parameter box if possible.

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Function Commissioning
Function commissioning is aimed at testing each component to see whether it is in normal operation
condition, as shown in Fig. 18. Press 【Up】,【Down】,【Left】,【Right】keys for selection of
corresponding components. Press 【OK】key for opening and press it again for closing. Correct
positioning of the protection door, digestion duct, water level cup and condensed water is for
supervision of the Kjeldahl Distillation Unit safety. Correct positioning is indicated by , and incorrect
positioning or no placement is indicated by . Press 【Return】key and all the components will close
down automatically.
Fig. 18
Safety Setting
Safety setting is mainly aimed at test for correct positioning of the protection door, digestion duct and
condensed water. You may not select the item not intended to be tested by the system in the test. The
item will indicate if it is selected, or it will indicate . Press 【OK】key for either selection or
cancellation of selection. When the setting is over, press 【Back】key for saving data and exit. See
Fig. 19.
Fig. 19
Help
Choosing [Help] in the original interface will display interface as shown in Fig. 20.
Fig. 20

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VIII. Regular Maintenance
1. Because during operation, the Kjeldahl Distillation Unit will perform the distillation process
that generates heat, a good ventilation and heatsink are required.
2. Wash away the sediments in the alkali solution bottle and boric acid bottle and clear
them up regularly.
3. Wipe out and clean the slot located in front of the instrument, in which the liquid may
accumulate.
4. Water scale may accumulate in the distilling bottle after a long time, which can influence
the heating efficiency. Follow the procedures listed below to remove it: Firstly, turn off the
instrument and disconnect the power cord; secondly, screw the plug out from the distilling
bottle and insert a small funnel in; thirdly, pour in the scale remover or glacial acetic acid to
remove the scale; After the cleaning is done, open the discharge valve located behind the
instrument to discharge the waste water completely and rinse the instrument repeatedly with
the distilled water.

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IX. Common Problems and Troubleshooting
X. Appendix
One-year limited warranty starts from the purchase day (the invoice-issuing date),
and does not cover the following situations:
1. The warranty has expired.
2. Any damage caused by the inappropriate operation.
3. Any damage caused by the disassembly that is not performed by authorized personnel.
4. Any damage caused by the inappropriate transportation or storage.
XI. Attention
1. Check the amount of distilled water before use and refill the bottle if necessary. The manufacturer
does not take any responsibility for any damage caused by the insufficiency of distilled water.
2. When the alkali solution or acid solution is made up, users must be cautious to avoid a burn injury
caused by chemical reagents.
3. It is prohibited to unplug the gas-liquid pipe when the Kjeldahl Distillation Unit is working, if
necessary, please open the bottle to release pressure.
4. Be careful about the glassware during transportation.
5. If the inside parts need repair, make sure the power cord is unplugged and wait for the distillation
system to cool down.
6. The outlet of waste-discharging pipe should be lower than the whole instrument to ensure a good
drainage.
7. Remove the alkali solution from its bottle and fill the water instead if the instrument will not be used
for a long time. Install nitrogen tube back to the instrument and start manual mode of adding alkali
solution to transfer the alkali solution stored in the pipe to the nitrogen tube. Then rinse the pipe with
the clear water to avoid the pipe clogging caused by the crystallization.
No.
Problem
Cause
Troubleshooting
1
No power
The fuse is burned or the power cord is not
plugged in firmly
Replace the fuse or correctly plug in the
power cord
2
Water in distilling bottle has
reached required level, but
no steam is generated and
heating indicator is still off
Malfunction in heating controller or something
is wrong with the wire connecting heating
controller and distilling bottle
1. Check whether the wires are loose.
2. Replace the heating controller
3
Unable to add alkali solution
1.The alkali solution is insufficient, the suction
tube is not able to reach the
alkali solution
2. There is no air pressure in alkali solution
bottle; air loop is not air-tight or the cap of
alkali solution bottle is not screwed firmly
into place
3.The air pump does not work
1.Add pre-made alkali solution into
alkali solution bottle
2. Check all connections and make sure
the cap of alkali solution bottle is
firmly screwed into place.
3. Replace the air pump
4
Unable to add
boric acid
As above mentioned
As above mentioned

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