Drawell K9860 Automatic Kjeldahl Analyzer Owner's Manual

User Manual
Please read the manual before installation and operation.
Drawell International Technology Limited
Chongqing Drawell Instrument CO,.Ltd
Add:Suite 2705,Building No.12,Shiyou Road No.1,Yuzhong District, Chongqing,China
Tel: 0086-023-63268643
Shanghai Drawell Scientific Instrument Co.,Ltd
Add : Suite 1117,Lane561 XiuChuan Rd.,PuDong New Area,Shanghai,China
Web : www.drawell.com.cn
Email : [email protected]
User Manual V3.3
Contents
I. Safety................................................................................................................1
II.Summary................................................................................................................6
2.1 Application...........................................................................................................6
2.2 Principles.............................................................................................................6
2.3 Operating procedures..........................................................................................8
III. Main performance................................................................................................9
3.1 Technical parameters..........................................................................................9
3.2 Use conditions......................................................................................................9
IV. Name of device components................................................................................10
V. Device installation methods.................................................................................12
VI.Function introduction.............................................................................................13
VII.Automatic test of samples...................................................................................30
VIII. Search of test record.........................................................................................34
IX. Routine maintenance of device…......................................................................34
X. Troubleshooting...................................................................................................35
XI. Cautions...............................................................................................................37
XII.Annex..............................................................................................................38
User Manual V3.3
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 instrument will cause the potential
safety hazard.
The instrument manufacturer has made the assessment on the possible
residual hazard:
Inexperienced personnel operate the instrument
Failure to operate the instrument according to the normal regulations
There is the warning information in this operating manual, and operators shall
know these residual hazards.
2. Safety
Warning: This instrument is only used for the 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 the 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. The operators shall wear the
rubber gloves, lab coats and goggles.
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Warning: Oral take-in of boric acid will cause the 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 and convulsions, and even
cause death if serious. It is easily absorbed by the damaged skin and causes
the 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 intense irritation and 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 (96-98%) 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 digestive tract will reach 100℃ during the
experiment. After completing the distillation, take the testing tube out with test
tube holder for avoiding scald.
Warning: Please use the power line provided by Hanon. Other power
lines will affect the safety performance of the instrument.
Warning: This instrument is equipped with the special grounding power
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User Manual V3.3
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 the environment with
the potential explosion risk.
Warning: In the case of not conflicting with the local waste disposal
regulations, waste liquor can be directly discharged into the sewer. Make sure
that the exhaust line is not bent or doesn't keep the upward flow and is as short
as possible, and the outlet end shall not be lower than the liquid level of the
sewer. (exhausting hot water below cold water will produce the noise). The
pipeline shall be fixed, because the waste liquid discharged from the system
has certain pressure.
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: Don't touch or open the protective door during the instrument
operation.
Notes: Make sure that the liquid solution will 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 Hanon service center.
Notes: This instrument shall be repaired by the personnel authorized
by Hanon. Hanon recommends using the original spare parts. If the spare parts
from other sources are used, the quality guarantee will be invalid.
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User Manual V3.3
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 the equipment meeting CE
requirements.
Notes: The unboxing, assembly and installation of the instrument shall
be completed by the personnel authorized by Hanon.
3. Guidance for waste disposal
It is not allowed to discard the electronic devices together with the
non-classified general waste. Improper disposal will produce the 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 Hanon.
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
Hanon.
The equipment is not refitted or repaired with spare parts not from Hanon, and
is not repaired by the personnel beyond those authorized by Hanon.
Only use the accessories and consumables provided by Hanon for from the
source recommended by Hanon.
The equipment can't be operated according to the way which is inconsistent
with the ordinary practice.
Only software authorized by Hanon can be installed in the PC of the equipment.
Use the external PC meeting the requirements recommended by Hanon.
Don't play game with PC, including the game installed together with operating
system.
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User Manual V3.3
The equipment shall conduct the correct maintenance according to the
requirements recommended by Hanon.
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.
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II. Summary
2.1 Application
Automatic Kjeldahl Analyzer is an automatic, smart device determining nitrogen
content based on Kjeldahl method. It can be widely used in food processing, feed
production, tobacco, livestock, soil fertility, environmental monitoring, medicine,
agriculture, scientific research, teaching, quality control and other fields for the test of
nitrogen or protein content with respect of macro and semimicro samples and can
also be used for the test of ammonium, volatile fatty acid / alkali, and so on. Upon test
of samples by using Kjeldahl method, the processes of digestion, distillation and
titration are required, wherein distillation and titration are main determination
processes with respect to Automatic Kjeldahl Analyzer.
Automatic Kjeldahl Analyzer is an automatic nitrogen determination system
integrating distillation and titration based on classic Kjeldahl method; the instrument
provides great convenience for lab staff in determining nitrogen-protein. It's safe,
reliable, simple for use and time-saving. A friendly user interface in English allows
easy operation and displays abundant information, enabling users to quickly master
the use of the instrument.
2.2 Principles
According to Kjeldahl principles, the determination requires three steps, which are
digestion, distillation and titration.
Automatic Kjeldahl Analyzer can automatically complete the processes of distillation
and titration. Upon the samples to be determined is fully digested, it's
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User Manual V3.3
subjected to the following chemical reactions on the instrument:
temperature steam
[1]. ( NH ) 2 SO4  2 NaOH high
 -

 Na 2 SO4  2 H 2 O  2 NH 3 
[2].
2 NH 3  4 H 3 BO3  ( NH 4 ) 2 B4 O7  5 H 2 O
[3].
( NH 4 ) 2 B4 O7  5 H 2 O  2 HCl  4 H 3 BO3  2 NH 4 Cl
The ammonia gas emitted during the reaction, together with the steam, is collected in
the receiving cup added with boric acid absorbing solution (containing mixed
indicator) after condensed by a condensing tube. Then the automatic titrator carries
on titration and record the volume of consumed standard titration acid. Based on the
volume of consumed standard titration acid, the calculating system calculates the
nitrogen content and crude protein content based on the following formulae.
Nitrogen content:
Crude protein content:
Wherein:
N (%) 
1.401  M
(V  V0 )
W
P (%)  N (%)  C
M=molar concentration of titration acid (mol/L);
W=sample weight (g);
V0= volume of consumed standard titration acid during blank sample titration (mL);
V= volume of consumed standard titration acid during sample titration (mL);
C=conversion coefficient for crude protein.
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2.3 Operating Flow Chart
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III. Main performance
3.1 Technical parameters
a. Sample capacity: solid≤5g, liquid≤20mL;
b. Measuring range: 0.1mg～200mg nitrogen;
c. Analysis time: 5～10 min/sample;
d. Recovery: ≥99.5%;
e. Titration accuracy: 1.0μL/step;
f. Repeated errors(RSD): ≤0.5%;
g. Data storage capacity: 1,000 pieces;
h. Consumption of condensate water: 1.5L/min;
i. External interface: USB, RS485;
j. Dimension size (length × width × height): 455mm × 391mm × 730mm;
k. Net weight: 38kg.
3.2 Use conditions
a. Power supply: 220 VAC ±10% 50Hz;
b. Rated power: 2KW;
c. Condensate water pressure: >0.02Mpa; flow: >1.5L/min;
d. Condensate water temperature: ≤ 20℃;
e. Ambient temperature: 10℃～35℃.
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IV. Name of instrument components
The instrument is a system conducting automatic distillation, titration, calculation,
printing, discharge and cleaning on the fully-digested sample and capable of
displaying operating procedures, with a microcomputer calculating results and a
printer outputting data. The system substantially consists of microcomputer controller,
steam generator, distilling system, alkali adding system, boric acid adding system,
titrating system, micro-printing, discharge system and cleaning system.
The structure of the instrument is composed as shown in the figure below:
Fig 3.1
1. Label 2. "Security door in-place" detector
water interface
3. Anti-splash bottle 4. Condensate
5. Distilling head 6. Fixed holder for digestion tube 7. Digestion tube
8. Digestion tube fixing block 9. Security door 10. Waste receiving tank 11. Touch
screen 12. Panel 13. Printer 14. Receiving cup
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15. Titration acid tank
User Manual V3.3
Fig 3.2
16. Condensate water inlet 17. Condensate water outlet 18. Discharge port
Fig 3.3
19. Power switch 20. Power plug
21. Alkali inlet 22 Boric acid inlet 23. Distilled
water inlet
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User Manual V3.3
Fig 3.4
1. Power indicator light 2. Heating indicator light 3. Alarm indicator light
V. Device installation methods
1. Inspection before installation
After the package is removed, check the instrument and its fittings as specified in the
appended packing list and inspect for damage. In case of damage, immediately
contact the manufacturer. (Please retain the damaged components)
2. Installation conditions
a. The device shall avoid direct sun radiation and places without extreme
temperature or moisture.
In general, the room temperature shall be kept between
10℃ and 35℃.
b. The device shall be installed at places adjacent to water source and drain tank and
provided with power sockets; the distance between the location of water supply valve
and power supply and the device shall be less than one meter for convenience of
operation.
c. The water supply shall comply with requirements of water pressure and water
temperature.
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User Manual V3.3
d. The drain tank shall at least be 50cm lower than discharge port of the device to
ensure smooth natural discharge.
e. The power arrangement shall comply with requirements of power supply. It shall be
provided with ground lead, and separate power switches and safeguards to ensure
users’ safety.
f. The device shall be installed far away from large electrical equipments, and the
operating location shall be free of quake, corrosive liquid and strong electromagnetic
field interference.
3. Installation
Lay the device flat on the test bench, leaving a distance of at least 20cm between the
back side of the device and the wall. Arrange a power socket within a distance of one
meter from the device, and meanwhile provide air-break switch, anti-creeping switch
and reliable grounding.
Connect pipelines according to each pipe interfaces listed in the back elevation of the
device. The condensate water inlet (16) is connected to the tap water valve;
condensate water outlet (17)discharge port (18) are respectively connected to the
drain tank through the pipe drains and discharge pipe to ensure smooth discharge.
VI. Function introduction
1. Function of operating panel
a. Display: True-color touch display.
b. Power indicator light（green）: it shows power supply status; the light is on upon the
device is powered on. When the light is on, it means the device enters into standby
status.
c. Heating indicator light（red）: When the light is on, it means the water in the steam
generator is being heated and the light turns off in non-operating status.
d. Alarm indicator light（yellow）: When the light is on, it means the failure of system
occurs or certain necessary conditions are not met upon distillation and the light will
be off when the system is in efficient working order. Note: the display will
simultaneously show alarming words and sound under alarming status.
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User Manual V3.3
2. The functions of the buttons of the printer are as follows
a. [SEL] button
Upon pressing this button, if the operating indicator light of the printer is on, it means
the printer is in line; if the light is off, it means the printer is off line. If printing is
desired, please maintain the print in line;
b. [LF] button
When paper needs to be reloaded, press [SEL] button to turn off the operating
indicator light of the printer; press [LF] button to make the printer automatically
loading paper; press this button again, the printer will stop loading paper; at last
press [SEL] again to turn on the operating indicator light of the printer, and the paper
loading process of the printer completes.
3. Safety performance
Protection upon condensate water supply is suspended: where the tap water supply
is cut off or suspended as the device is running, the device will automatically stops
operation to prevent spraying of heating steam scalding people.
Protection upon steam generator lacks water: the steam generator is provided with
water refilling functions; when the tank supplying the steam generator is lacking water,
the steam generator will automatically stops operation to prevent the damage from
heating without water.
Protection of security door: a transparent anti-corrosive security door enables
observation of the whole process of distillation; if the security door is not closed upon
operation, the device will lock up the operating button to provide safety protection.
Protection upon steam generator is under overpressure: the steam generator has
protective functions against overpressure, in case of overpressure, the pressure
sensor will automatically cut off the power supply to prevent explosion due to
overpressure.
4. Operation of device functions
The operations of functions attainable by the device in testing samples are as follows:
diluting, adding reagent, distilling, titrating, discharging waste, result calculating and
printing.
Diluting: add distilled water into the digested sample in the digestion tube to dilute.
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User Manual V3.3
Adding reagent: includes adding of alkali solution, boric acid absorption solution,
titration acid, etc.
Distilling: add hot steam into the sample in the digestion tube to distill the ammonia of
sample.
Titrating：titrate absorption liquid when distilling or complete distilling.
Discharge waste: discharge wastes in the digestion tube, receiving cup.
Result calculating and printing: calculate the result and print it according to operation.
5. Operation of function interface
Main interface
After the startup animation, six functions will be displayed, including [Test], [Clean],
[Search], [Debug], [Setup], [Help]. Press corresponding icon to enter respective
interface. See Fig.5.5.1
Fig. 5.5.1
Press [Test], the menu system will automatically enter into operating mode interface,
[Automatic test] After setting experimental parameters, the device will carry out
automatic experimental test.
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User Manual V3.3
Fig. 5.5.2
After inputting corresponding experimental parameters, press [OK] to enter
experiment interface and start the experiment. The steps of experiment are
respectively: add diluting water, add boric acid, add alkali, distill, titrate, calculate and
print, discharge, digestion tube cleaning and receiving cup cleaning, of there the
functions of digestion tube cleaning and receiving cup cleaning are set up as required
in [Setup] interface before the experiment starts.
To ensure the safety of the experiment, the system collects and displays all aspects
of status information with respect to the device on a real-time basis during the test
process, such as level of steam generator, security door in place, presence of
condensate water, etc. If any abnormal condition is detected, the task will be
suspended. For example, upon lack of condensate water, the following interface will
appear. See Fig. 5.5.3.
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User Manual V3.3
Fig. 5.5.3
The system displays current operating items and real-time values on a real-time
basis. When the set value is reached, the system will stop the current function and
turn to the next experimental function. If the parameter is set with value “0”, then the
system will not start corresponding function. Taking adding boric acid as an example,
when a parameter is set, the system will start filling of boric acid. See Fig.5.5.4.
Fig.5.5.4
When a parameter is set, after filling of boric acid is completed, the system will start
filling of diluting water and display that diluting water is being added.
Note: the dilution function of the device is to dilute the digested sample in the
digestion tube by adding distilled water.
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User Manual V3.3
Fig.5.5.5
After parameter setting and dilution water adding completed, Alkali adding starting,
the display (figure 5.5.6) as follow：
Fig. 5.5.6
During foregoing operation, the experiment can be suspended at any time by the
operator as necessary. The experiment can be either continued or quitted after
suspension. If the alkali is not sufficient due to certain causes, then the experiment
can be suspended upon distillation. Press [Add alkali] to add fixed volume of alkali
solution. A 5ml solution can be added for each pressing of [Add alkali]. Press
[Continue] to continue the experiment. See Fig. 5.5.7.
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User Manual V3.3
Fig. 5.5.7
After completion of adding alkali, the system will start the distillation process. If the
time parameter of distillation is set 0, then the system will not start the distillation
process; if certain parameter is set, the distillation process will be automatically
started; meanwhile the suspend or back can be attained. See Fig. 5.5.8.
Fig. 5.5.8
During the process of distillation, in case of abnormal conditions, it will be notified,
such as overheating of ammonia water, See Fig.5.5.12, overheating of steam
generator, See Fig. 5.5.9.
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User Manual V3.3
Fig. 5.5.9
Upon the system enters into the process of titration, See Fig. 5.5.10.
Fig. 5.5.10
In case discharging and cleaning are set in [Setup], then system will automatically
discharge and clean after completion of titration. The cleaning of digestion tube and
receiving cup will be respectively carried out following the discharging of the same.
The system can not suspend or back upon commencement of cleaning or
discharging till the completion of cleaning or discharging. See Fig. 5.5.11.
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User Manual V3.3
Fig. 5.5.11
After completion of cleaning, it will enter into the titration result interface, wherein the
titrated volume, nitrogen content and protein content will be simultaneously displayed.
Under such interface, printing can be carried out. See Fig.5.5.12.
Fig.5.5.12
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User Manual V3.3
Cleaning
Choose [Cleaning], with interface as shown in the figure, including , Receiving cup
cleaning, Alkali pipeline cleaning, Boric acid pipeline cleaning, Acid washing, you will
see this interface when you access cleaning page, See Fig. 5.5.13.
Fig. 5.5.13
For example, choose [Receiving cup cleaning], click on [Receiving cup cleaning] to
start cleaning of receiving cup; the interface displays "cleaning receiving cup "; upon
touching [Back], the cleaning stops and the interface returns to cleaning function
interface. See Fig. 5.5.14.
Fig. 5.5.14
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Search
Choose [Search] to enter into search interface for historical record, input sample No.
to display corresponding experiment results and storage time. In case no reference
number is input, the system will display the record of latest experiment; the system
will display corresponding record following manual input of reference number (Range
of sample No.: 1-1000). [Print] operation is available; click on Print to print data of
corresponding reference number Clicking on menu icon can exit search interface and
return to the main interface. Also, you can click on other icons in the tool bar as
necessary to enter into other function interfaces. See Fig. 5.5.15.
Fig. 5.5.15
Debug
Choose [Debug] to enter into the debug interface, which tests all electronic parts
within the device. With respect to the back of corresponding button, √ indicates
initiation, × indicates closure; the white icon represents detection of level sensors, etc.
√ and × indicate the present working status of sensors. For example, √ appears upon
detection of security door in place, otherwise × appears. After completion of choosing,
the debug of the device commences. See Fig. 5.5.16. Choose [Back] to return to the
previous interface.
Note: the consequences arising from unauthorized use of debug interface will
be borne by the user; this interface is only for use by technicians with the
manufacturer.
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User Manual V3.3
Fig. 5.5.16
Setup
Choose [Setup] to enter Setup interface, wherein setup of the following functions can
be attained:
[Water flow test] determines whether to detect the presence of condensate water
during the test.
[Receiving cup cleaning] with respect to automatic test which determines whether to
carry out receiving cup cleaning after titration.
[Color calibration] is used for titration sensor calibration.
[Titrator calibration] is conducted by titrator.
[Calibration coefficient] upon measuring samples, there will be system errors due to
connection to different systems. To ensure accurate measurement, a deviation
calibration coefficient is established to enable calibration by the user.
[System time] is used to set up system time.
[Historical data] reset storage data.
Set up corresponding function in this interface before the commencement of
experimental test. See Fig. 5.5.17.
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User Manual V3.3
Fig. 5.5.17
Water flow test
Choose [Water flow test] to display corresponding dialog box. Choosing [Yes], [OK]
means the system will suspend the experiment in case no water is present in the
condensate water tube during the test till the presence of water. Choosing [No], [OK]
means there will be no alarm regardless of presence of water. Pressing [Back] will
maintain the original setting and enter into the original Setup interface. See Fig.
5.5.18.
Fig. 5.5.18
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Receiving cup cleaning
Choose [Receiving cup cleaning]to enter into choice interface; choose [Yes], [OK] to
enable receiving cup cleaning after completion of test; choose [No], [OK] to disable
receiving cup cleaning after completion of test; choose [Back] to maintain the original
setting and return to the Setup interface. See Fig. 5.5.20.
Fig. 5.5.20
Calibration coefficient
Choose [Calibration coefficient] to enter into the following interface, wherein
corresponding calibration coefficient is to be input. Press [OK] to enable calculation in
the process of test based on the input coefficient. See Fig. 5.5.21.
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User Manual V3.3
Fig. 5.5.21
Color calibration
Choose [Color calibration] to enter into color calibration interface, wherein the color
calibration is carried out with respect to the recognition of titration end-point color
change. See Fig. 5.5.22 for the interface.
Note: the consequences arising from unauthorized use of debug interface will
be borne by the user; this interface is only for use by technicians with the
manufacturer.
Fig. 5.5.22
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Titrator calibration
Make the special receiver equipment ready before titrator calibration. Choose [Start]
with respect to [Titrator calibration], the titrator to absorb fluid first, after alarming, the
titrator pushes out a fixed volume of solution to the receiver equipment; then the input
data of actually pushed out volume is obtained through weighing. Press [OK] to
complete the process of the titrator calibration. In case of choosing [No], [OK] or
[Back], it will maintain the original setting and enter into the initial Setup interface.
See Fig. 5.5.23.
Note: the consequences arising from unauthorized use of debug interface will
be borne by the user; this interface is only for use by technicians with the
manufacturer.
Fig. 5.5.23
System time
Choose [System time] to display dialog box for time setting, and input right time.
Press [OK] to complete time setting; [Back] to maintain original setting and enter into
the original Setup interface. See Fig. 5.5.24.
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Fig. 5.5.24
Historical data
Choose [Historical data] to enter into choice interface, choose [OK] to delete all
historical date, choose [Back] to exit. See Fig. 5.5.26.
Note: Once reset historical data it can't recover, please careful operate
carefully.
Fig. 5.5.26
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Help
Choosing [Help] in the original interface will display interface as shown in Fig. 5.5.27.
Fig. 5.5.27
VII. Sample test
1. Reagent preparation
（ 1 ） Boric acid solution (20g/L): weigh and dissolve 20.00g boric acid in distilled
water, with volume defined in a 1,000mL measuring flask; shake it till evenly mixed.
Add 100:1 mixture of methyl red and bromcresol green and make it uniformly mixed.
（ 2 ） Sodium hydroxide solution (400g/L): weigh and dissolve 400.00g sodium
hydroxide in distilled water, with volume defined in a 1,000mL measuring flask; shake
it till evenly mixed.
（3）Standard titration solution
a) Standard titration solution of sulfuric acid [c(1/2H2SO4)=0.1000 mol/L]: take and
dilute 2.73mL concentrated sulfuric acid (density: 1.8419g/mL) with distilled water,
with volume defined in a 1,000mL measuring flask; shake it till evenly mixed, and
calibrate.
b) Standard titration solution of hydrochloric acid: take and dilute 8.30mL
concentrated hydrochloric acid (concentration: 36%-38%) with distilled water, with
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volume defined in a 1,000mL measuring flask; shake it till evenly mixed, and
calibrate.
（ 4 ） Standard solution of ammonium sulfate: take and dissolve 6.6065g dried
ammonium sulfate (G/R) with distilled water, with volume defined in a 1,000mL
measuring flask; shake it till evenly mixed.
（ 5 ） Mixing 1 part of methyl red was dissolved in 0.l% ethanol solution of 95%
ethanol (1g / L) and 5 parts was dissolved in 0.l% bromocresol green ethanol solution
of 95% ethanol (1g / L), please make it just before use.
Note: sulfuric acid (H2SO4), copper sulfate (CuSO4), potassium sulfate (K2SO4)
shall be prepared for the digested sample.
Tips: Weigh 0.5-1g sample; add in 8mL-10mL concentrated sulfuric acid; and
add in copper sulfate: 3.2g potassium sulfate of 1:15 mixture. (Refer to national
standard and relevant industry standards for specific dosage)
When using Kjeldahl Analyzer, it is suggested as follows in order to reduce the
measurement error of the device to the greatest extent:
(1) The pH of 2% boric acid absorption solution shall be regulated to 4.5;
(2) The reaction between strong acid and strong base is vigorous, thus it's suggested
to dilute it by first adding 10-20 ml distilled water;
(3) The volume of 40% or approximate concentration of sodium hydroxide to be
added is advantageously 4 times of that of concentrated sulfuric acid;
(4) Upon distillation, the total volume of liquid in the digestion tube is advantageously
kept below 1/3 of the capacity of the digestion tube;
2. Reference value for test
The nitrogen content in the sample shall be considered in weighing sample. Where
sample features high nitrogen content, fewer samples shall be taken provided the
weighing error is reduced to the greatest extent. In case of low nitrogen content in
sample, more samples shall be weighed. It can be generally advantageous that the
weighed sample contains 15-50mg nitrogen.
Upon digestion of sample, add 10mL distilled water to dilute the digested sample.
After it is fully cooled and leave it for measurement. Generally 0.1mol/L standard acid
is taken as titration acid.
Table I Relationship between standard titration acid to be chosen and nitrogen
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User Manual V3.3
content in sample to be measured
3. Test parameter setup
Molar
concentration
of
standard titration acid (mol/L)
Nitrogen content in sample to
be measured (mg)
0.02
0.1～20
0.1
15～100
0.15
30～200
(1) Install the device, and properly connect the pipeline.
(2) Turn on the condensate water; place an empty digestion tube, start the device to
vaporize water for 5-10 min in order to clean the pipeline and stabilize the steam flow.
(3) Put the digestion tube containing digested sample in place and close the security
door. Set up corresponding parameters and functions to start the test. The device
simultaneously starts the real-time test function. Add boric acid absorption solution,
diluting water and concentrated alkali solution in the device. Ammonia gas emitted
from distillation of steam is absorbed via condensate boric acid; and then standard
acid is used for titration.
(4) After completion of the test, the result is displayed. Printing, automatic discharge
and automatic cleaning are attainable. It returns to initial parameter input interface
after completion of the test.
4. Device calibration
(1)Meaning of calibration coefficient K
Upon measuring sample by using the device, there will be system error due to
connection to different systems. Thus, in order to make accurate measurement, a
error calibration coefficient K shall be established. The users can carry out calibration
by themselves.
The relationship between nitrogen content calculation and K value:
N% 
1.401  M  (V  V0 )  K
W
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User Manual V3.3
(2)Measurement of standard sample
Ammonium sulfate (purity level: at least A/R) may be selected as a standard sample
for device calibration. Both liquid and solid samples can be used for measurement.
Solid sample: weigh and put 0.1-0.2g ammonium sulfate into the digestion tube for
direct measurement on the device.
Liquid sample: weigh 6.6065g ammonium sulfate and define its volume to 1,000mL
with distilled water, producing a standard solution with 1.4mg/mL nitrogen content.
Use a volumetric pipette to take a standard sample with nitrogen content close to that
of the actually-measured sample. Upon blank measurement, choose 1 as K value.
(3) Calculation of K
It can be derived from above calculating formula that:
KN
N1
N: Nitrogen content in the standard sample (%);
N1: Nitrogen content in the standard sample as measured by the device (%).
For example: take three standard solution samples, each 10ml 1.4mg/mL of standard
solution and respectively obtain nitrogen content in the standard sample: N1, N2, N3.
Calculate K1, K2, K3 based on calculating formula for K, and obtain a final K which is
an arithmetical mean of the three.
After the calibration coefficient K is calculated, input this coefficient in [Calibration
coefficient] in the sample parameter input interface, and re-measure with a standard
sample. In case the error remains, it shall be re-calibrated. (It's suggested to
approximate the nitrogen content in the standard solution to that in single sample of
substance to be measured in the experiment.)
Where corresponding crude protein content is required, a protein conversion
coefficient shall be input in the test parameters, and the device will automatically
calculate the crude protein content. When crude protein content is undesired, please
set the protein conversion coefficient to 0. Thus the obtained crude protein content
will be 0 and there will be no crude protein content the report to be printed.
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User Manual V3.3
VIII.Search of test record
The device can store 1,000 records for reference to previous test record by the user.
After completion of sample test, the sample No. will be automatically incremented.
After the record reaches the maximum storage capacity (1,000 pieces), it will restart
to record from reference number one (the previous first record). The test record can
be stored for a long period (typically greater than 10 years), with a circular storage of
1,000 test records for search and print by the user.
IX. Routine maintenance of device
1. The device socket shall be kept clean and dry and away from acid and alkali
solution to ensure insulation high input impedance performance.
2. The alkali solution tank, boric acid solution tank, distilled water tank, titration acid
tank shall be cleaned on a regular basis.
3. In case any liquid remains in the waste receiver tank at the bottom of security door
of the device, please immediately clear it way.
4. There will be scale deposit in the distillation bottle after the device is used for a
long period, which will affect heating efficiency (it's suggested to clean for every 6
months). The cleaning frequency may be increased in case of frequent use. The
scale deposit is removed by introducing a detergent or a certain concentration of
weak acid solution in through distilled water pipeline and discharged via the distilled
water drain valve. Then the pipeline will be properly connected following several
flushing using the distilled water.
5. When the titration acid concentration is modified, the titration acid in the pipeline
and the titrator is fully discharged by manual titration, and new acid is used to flush
for at least 6 times and discharged immediately.
6. In order to prolong the service life of the glass components, please clean it at least
once after completion of work every day, i.e., 100mL water is added and evaporated
for 5 min.
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User Manual V3.3
7. There may be bubbles in the pipeline of the piston pump, please remove it before
experiment.
8. It is advantageous to calibrate the titrator at least once a year.
9. Fix the pipeline connected to the discharge ports of the steam generator and the
digestion tube to prevent splash of high temperature corrosive liquid.
10. The receiving cup and alkali pump shall be cleaned after completion of
experiment.
11. When the device is heated with full power and sufficient condensate water, the
liquid discharged shall not be less than 150mL for discharge time of 5 min.
12. Wear protective glasses and gloves upon maintenance on the device.
X. Troubleshooting
Serial No.
Failure
1
The device can not be
powered on
2
There's no
distillation
3
steam
when
Alkali, boric acid and
dilution water can not be
added properly
Cause
Solution
1. Shortage of power
supply ；
2. power line not properly
connected;
3. Fuse is broken.
1.Steam generator water
shortage；
2.The heating controller
fails;
3. The conductor wire
between the heating
controller and the
distillation bottle is not well
connected;
4.Heating tube fails;
5. Pressure-head switch
fails;
6.Temperature protection
switch fails;
7. Steam valve fails.
1.Insufficient solution in
the
solution tank , and
the pipette is located
above the level;
2.The solution adding
pipeline is not air-tight;
3. The alkali adding pump
can not work in order; can
1.Cheak the power
supply；
2.Properly connect the
power line；
3. Change the fuse.
1. Add water to bucket，
then press “continue”;
2. Change the heating
controller;
3. Check whether the
conductor wire is
loosened;
4. Change heating tube;
5. Change
pressure-head switch;
6.Change temperature
protection switch;
7. Change steam valve.
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1. Add solution in the
solution tank;
2. Check the connectors
for the pipeline are sealed;
3. Clean the solution
pump ;
4. Change the pump;
5. Change solenoid
User Manual V3.3
4
5
6
7
Titration can not be carried
out
Unstable
data
measurement
Wrong measurement data
The test is paused
not be started; the pipeline
is blocked;
4. The pump can not work
5. Solution tank is
damaged.
1. Insufficient titration acid;
2. Failure in titration
system ;
3. Clogging of titration
electromagnetic valve.
valve.
1． The receiving cup is
not clean;
2． The steam generator
is not clean;
3. The position of burette
is not installed correctly.
4. Too much liquid in the
digestion tube;
5. Insufficient alkali;
6. Titration color error.
1. Clean receiving cup;
2.Clean steam generator
3. Install burette
correctly;
4. Reduce liquid in the
digestion tube;
5.Add sufficient alkali;
6.Calibrate the color again.
1. Wrong input of titration
acid concentration;
2. Inaccurate device
calibration.
1. Input hydrogen ion
concentration as titration
acid concentration;
2. Recalibrate the device.
1. The door is not closed
well;
2.Insufficient condensate
water;
3.Insufficient liquid in
steam generator;
4.Overtemperature of
steam generator;
5. Overflow of receiving
cup;
6.Overtemperature of
receiving liquid.
1.Close the door well;
2.Fixed the digestion tube
well;
3.Cheak condensate
water;
4.Cheak steam
generator;
5.Cheak receiving cup;
6.Cheak condensate
water.
1. Add titration acid;
2. Change the titration
system;
3.Change electromagnetic
valve.
The device is warranted for a year from the date of purchase (subject to the date
on the issued invoice) except for the following conditions:
1. The warranty period expires;
2. Damage caused by misuse;
3. Damage caused by disassembly unauthorized by the manufacturer;
4. Damage caused by improper transportation and custody.
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User Manual V3.3
XII. Cautions
1. Make sure there's sufficient water in the distilled water tank before using the device
to ensure normal operation of the device. The manufacturer will not be responsible
for device failure caused by insufficient distilled water.
2. The interior storage of the device stores data based on sample No.. Notice the
setting of sample No.; the storage is reusable, with a sample No. ranging from 1 to
1000. The user shall not be free to modify the sample No..
3. The preparation of alkali solution and acid solution requires careful operation to
avoid being burnt by chemical reagent.
4.The device contains glassware, which requires careful handling during
conveyance.
5. Upon repairing internal components of the device, make sure to turn off the device
and plug off the power line and wait for the cooling down of the distillation system.
6. The outlet of the discharge pipe shall be located below the installation location of
the device to ensure smooth discharge.
7. Upon the device is left unused for a long period, the alkali solution in the alkali
solution tank shall be replaced with distilled water; the digestion tube is put in place;
the alkali is added manually to remove the alkali solution in the pipeline and the
pipeline is cleaned to prevent crystallization clogging.
8. A blank test shall be carried out before start-up to clean the pipeline of the device in
order to ensure accurate test results.
9. The device has been subject to test before delivery, thus it's normal for presence of
residual solution.
10. It is suggested that the maximum solution volume in the digestion tube shall not
exceed 2/3 of the capacity of the digestion tube.
Note: before using the device, please turn on the condensate water and
examine whether solutions in each solution tank (alkali solution tank, boric
acid solution tank, distilled water tank and titration acid tank) meet the
requirements of the test, or otherwise, add immediately.
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User Manual V3.3
XIII. Annex
The assembly and disassembly of the digestion tube is illustrated as follows:
Fig.1
Steps of installing the digestion tube:
First lift up the fixed tube handle, and put the mouth of the digestion tube in place
from below and pull down the fixed tube handle.
Steps of dismantling the digestion tube:
Lift up the fixed tube handle and remove the digestion tube in a vertically downward
direction.
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Drawell International Technology Limited
Chongqing Drawell Instrument CO,.Ltd
Add:Suite 2705,Building No.12,Shiyou Road No.1,Yuzhong District, Chongqing,China
Tel: 0086-023-63268643
Shanghai Drawell Scientific Instrument Co.,Ltd
Add : Suite 1117,Lane561 XiuChuan Rd.,PuDong New Area,Shanghai,China
Web : www.drawell.com.cn
Email : [email protected]
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