Knauer K-7400S User manual

Freezing Point Osmometer
Instructions
K-7400S Semi-Micro Osmometer
Document no. V3700

Note: For your own safety, read the instructions and observe the war-
nings and safety information on the device and in the instructions. Keep
the instructions for future reference.
Note: In case you require this instruction in another language, please
submit your request including the corresponding document number via
e-mail or fax to KNAUER.
Do you have questions about the installation or the operation of your
instrument or software?
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Contact your local KNAUER partner for support:
www.knauer.net/en/Support/Distributors-worldwide
Support in Germany
(Austria & Switzerland on case-to-case basis):
Phone: [phone] (workdays 9-17h CET)
Fax : [phone]
Email: [e-mail]
KNAUER Wissenschaftliche Geräte GmbH
Hegauer Weg 38
14163 Berlin
Germany
Phone: [phone]
Fax: [phone]
Internet: www.knauer.net
E-Mail: [e-mail]
Document number: V3700
Version number: 2.4
Release date: 2020/09/18
Translation of the original edition
The information in this document is subject to change
without prior notice. For the latest version of the instructions,
visit our website: www.knauer.net/library.
The printed versions of our instructions are printed according to
Blue Angel standards (www.blauer-engel.de/en/uz195).
This document contains confidential information and may not be
reproduced without written consent of KNAUER Wissenschaftliche
Geräte GmbH.
© KNAUER Wissenschaftliche Geräte GmbH 2020
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ii
Semi-Micro Osmometer K-7400S instructions, V3700
Table of Contents
1. Product information ...................................................................4
1.1 General ........................................................................4
1.2 Intended use....................................................................4
1.2.1 Operating ranges .....................................................4
1.3 Views ..........................................................................5
1.3.1 Front view ............................................................5
1.3.2 Keypad. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3.3 Rear view .............................................................6
2. Scope of delivery .....................................................................7
3. Basic safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
3.1 Signal words ....................................................................8
3.2 Decontamination ................................................................9
4. Symbols and signs ...................................................................10
5. Unpacking and setup .................................................................11
5.1 Location requirements ..........................................................11
5.2 Unpacking the device ...........................................................11
5.3 Power supply ..................................................................12
6. Startup .............................................................................14
7. Operation ...........................................................................15
7.1 Connecting the measuring head..................................................15
7.2 Standby position of measuring head ..............................................16
7.3 Measurement principle and process ..............................................16
7.4 Switch on ......................................................................18
7.5 Menu guide....................................................................18
7.6 Preparing a measurement .......................................................20
7.6.1 Measurement preparation process......................................20
7.7 Calibration.....................................................................21
7.7.1 Pre-calibration .......................................................21
7.7.2 Measurement calibration ..............................................22
7.8 Measuring sample solutions .....................................................23
7.8.1 Performing a sample measurement .....................................23
7.9 Important operating notes .......................................................24

Semi-Micro Osmometer K-7400S instructions, V3700
Table of Contents iii
8. Functionality tests ....................................................................26
9. Troubleshooting .....................................................................27
9.1 System messages...............................................................27
9.2 Self-freezing of the sample.......................................................27
9.3 Non-freezing of the sample ......................................................28
10. Using the EuroOsmo 7400 Software ...................................................29
10.1 Installation.....................................................................29
10.1.1 Hardware installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
10.2 Main screen....................................................................30
10.3 Icons..........................................................................31
10.4 Run Settings ...................................................................31
10.5 Sample list.....................................................................32
10.6 Setup .........................................................................33
10.7 Working parameters ............................................................33
10.8 Report & Graph ................................................................35
10.9 Search function.................................................................35
11. Maintenance and care ................................................................37
11.1 Cleaning the stirring wire and the thermistor .......................................37
11.2 Function checks of cooling capacity...............................................37
11.2.1 Reference thermometer ...............................................38
11.3 Transport ......................................................................38
11.4 Storage .......................................................................39
11.4.1 Disconnecting the power supply .......................................39
12. Technical data .......................................................................40
12.1 Main features ..................................................................40
12.2 Communication ................................................................40
12.3 General .......................................................................41
13. Repeat orders .......................................................................42
14. Legal information ....................................................................43
14.1 Transport damage ..............................................................43
14.2 Warranty conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
14.3 Warranty seal ..................................................................44
14.4 Declaration of conformity........................................................44

Semi-Micro Osmometer K-7400S instructions, V3700
Table of Contents iv
14.5 Disposal.......................................................................44
14.6 KNAUER software license agreement..............................................44

4
Semi-Micro Osmometer K-7400S instructions, V3700
1. Product information
1.1 General
The Semi-Micro Osmometer K-7400S allows the easy and fast determina-
tion of the osmolality of various aqueous solutions. In addition, the freez-
ing point depression of such samples can be measured.
The proven technology of freezing point determination in combina-
tion with the robust and intelligent design of the device allows fast and
reproducible measurements. The instrument is equipped with a peltier
cooler and an integrated microprocessor controlling the automated
measurement.
The freezing point Osmometer is a standalone device that optionally can
be equipped with a printer. Furthermore, the device can be controlled via
the EuroOsmo 7400 software.
1.2 Intended use
Note: Only use the device for applications that fall within the range of
the intended use. Otherwise, the protective and safety equipment of the
device could fail.
Freezing point osmometers (FPO) are versatile for analysis of aqueous
solutions of various origin. Only a small sample size is needed and results
are generated fast and reproducible.
A limitation of FPOs is the analysis of high viscous samples as osmolality
of these samples can not be measured. Also samples of high molality or
colloidal solutions can not be analyzed.
1.2.1 Operating ranges
The Semi-Micro Osmometer K-7400S can be used for example in the fol-
lowing application areas:
pharmaceutical analysis
environmental analysis
beverage analysis

Semi-Micro Osmometer K-7400S instructions, V3700
Product information 5
1.3 Views
1.3.1 Front view
Legend:
1
Measuring head
2
LCD display
3
Keypad
Fig. 1: Front view
1.3.2 Keypad
Buttons Function
START/STOP Starts a measurement or calibration run. If this
button has no specific function on the screen, it
causes to return on the main screen.
With this button, every running measurement
can be interrupted.
VIB Activates the stirring wire. During RUN and
CALIBRATE, the button is without any function.
Arrows Cursor navigation buttons for parameter or
value selection
3
2
1

Semi-Micro Osmometer K-7400S instructions, V3700
Product information 6
1.3.3 Rear view
Legend:
1
RS-232 connector
2
Measuring head con-
nector
3
Ventilator
4
Power switch
5
Power connector
Fig. 2: Rear view
5
4
3
2
1

7
Semi-Micro Osmometer K-7400S instructions, V3700
2. Scope of delivery
Note: Only use original parts and accessories made by KNAUER or a
company authorized by KNAUER.
Freezing Point Osmometer K-7400S
Power cable
RS-232 connection cable
Measuring head
Pack of sample tubes
400 mOsmol/kg calibration solution
850 mOsmol/kg calibration solution
Lint-free cleaning tissue
Valid documents:
K-7400S instructions (document no. V3700)
Declaration of conformity

8
Semi-Micro Osmometer K-7400S instructions, V3700
3. Basic safety instructions
The instructions address persons who are qualified as chemical laborato-
ry technicians or have completed comparable vocational training.
The following knowledge is required:
Knowledge regarding the health risks of chemicals
Participation during an installation of a device or a training by the com-
pany KNAUER or an authorized company.
When working with the device, take measures according to lab regula-
tions and wear protective clothing:
Safety glasses with side protection
Protective gloves
Lab coat
All safety instructions in the instructions
The environmental, installation, and connection specifications in the
instructions
National and international regulations pertaining to laboratory work
Original spare parts and tools made or recommended by KNAUER
Good Laboratory Practice (GLP)
Accident prevention regulations published by the accident insurance
companies for laboratory work
Power cable: Defective power cables are not to be used to connect the
device and the power supply system.
Power strip: If several devices are connected to one power strip,
always consider the maximum power consumption of each device.
Power supply: Only connect devices to voltage sources, whose voltage
equals the device‘s voltage.
Never use the system in potentially explosive atmospheres without
appropriate protective equipment. For further information, contact the
Technical Support of KNAUER.
At any time, take the device completely out of operation by either switch-
ing o the power switch or by pulling the power plug.
The device may be opened by the KNAUER Technical Support or any
company authorized by KNAUER only.
3.1 Signal words
Possible dangers related to the device are divided into personal and
material damage in this instructions.
Lethal injuries will occur.
Serious or moderate injuries can occur.
Minor injuries can occur.
Device defects can occur.
Target group
Safety equipment
What must be taken
into account?
Where is use of the
device prohibited?
Secure
decommissioning
Opening the device

Semi-Micro Osmometer K-7400S instructions, V3700
Basic safety instructions 9
3.2 Decontamination
Contamination of devices with toxic, infectious or radioactive substances
poses a hazard for all persons during operation, repair, sale, and disposal
of a device.
Life-threatening injuries
Health danger if getting in contact with toxic, infectious or radio-active
substances.
Before disposing of the device or sending it away for repair, you are
required to decontaminate the device in a technically correct manner.
All contaminated devices must be properly decontaminated by a special-
ist company or the operating company before they can be recommis-
sioned, repaired, sold, or disposed of. All materials or fluids used for
decontamination must be collected separately and disposed of properly.
Devices without a completed service request and decontamination report
will not be repaired. If you would like to return a device to
KNAUER, make sure to enclose a completed service request form with
the device: www.knauer.net/servicerequest.
Service request form

10
Semi-Micro Osmometer K-7400S instructions, V3700
4. Symbols and signs
The following symbols and signs can be found on the device or in the
instructions:
Symbol Meaning
Warnng Signs Electric shock hazard
Electrostatic discharge hazard, damages to sys-
tem, device, or components can occur.
Biohazard
CE Mark A device or system marked with CE fulfills the
product specific requirements of European
directives. This is confirmed in a Declaration of
Conformity.
Note Notes provide useful tips or information worth
knowing.

11
Semi-Micro Osmometer K-7400S instructions, V3700
5. Unpacking and setup
This chapter describes all preparatory steps prior to start-up.
Note: To ensure structural stability, the device is not intended to be sta-
cked on or below other devices.
5.1 Location requirements
The intended use be ensured only if the requirements for ambient condi-
tions of the operating environment are met. You will find the ambient
conditions in the chapter „Technical data“ (see page 40).
Position the device on a level surface.
Protect the device against direct exposure to sunlight.
Set up the device at a location not exposed to air drafts such as air
conditioning systems.
Do not set up the device near to other machines that cause floor
vibrations.
Keep the the devices away from high frequency sources. High frequen-
cies may compromise measurement values.
At least 5cm, if there is another device on one side.
At least 10cm, if there are devices set up on both sides.
At least 15cm to the cooler fan on the rear.
The device should not be exposed to major temperature fluctuations
during measurement.
Device defect
The device overheats at exposure to sunlight and insucient air circula-
tion. Device failures are very likely.
Set up the device in such a way that it is protected against exposure
to direct sunlight.
Leave room for air circulation: See paragraph „space requirements“.
5.2 Unpacking the device
At the factory, all KNAUER devices are carefully packed for safe transport.
After unpacking, check all device parts and accessories for signs of dam-
age during transport and if necessary assert claims for damages immedi-
ately to the transport company.
The complete listing of consumable and spare parts can be found in sec-
tion „13. Repeat orders“ on page 42.
Check packaging for damage caused during transportation. If necessary,
put forward any claim for damages to the carrier.
Utility knife
General purpose
Space requirements
Ambient temperature
Prerequisite
Tools

Semi-Micro Osmometer K-7400S instructions, V3700
Unpacking and setup 12
Bruising danger
Damage to the device by carrying or lifting it on protruding housing
parts. The device may fall and thus cause injuries.
Lift the device only centrally on the side of the housing.
1. Set up the package in such a way that you can read the label. Using
the utility knife, cut the adhesive tape and open the packaging.
2. Remove the foam insert. Take out the accessory kit and the
instructions.
3. Open the accessory kit and check the scope of delivery. In case any
parts are missing, contact the Technical Support.
4. Clasp the device from below, lift it out of the packaging and place it
on its feet.
5. Check the device for signs of damage that occurred during transport.
In case you notice any damage, contact the Technical Support.
6. Place the device in its site of operation and remove protective foil.
Store packaging and keep the included packing list for repeat orders.
5.3 Power supply
Use only the enclosed power cable to connect the device to the mains
to make sure that the specifications stated in Technical Data are met. But
check beforehand to use power cables admitted for use in your count-
ry. Replace defective power cables only with accessories from KNAUER.
Detachable power cables must not be replaced with dierent cable types.
The maximum power input is 70 watts.
Electronic defect
Electronic hazard when using an identically constructed power adapter
from another manufacturer.
Only use spare parts and accessories from KNAUER or a company
authorized by KNAUER.
Note: The nominal capacity of the connected devices must be maximum
50% of the power supply to account for larger inrush currents when swit-
ching on the modules.
The electrical power supply at the installation site must be connected
directly to the nearest main power line.
The power must be free from ripple, residual current, voltage peaks
and electromagnetic interference.
The connectors for the mains voltage are grounded accordingly.
The device receives sucient power with reserve capacity.
The device is intended for use with AC power networks of 100–240 V.
Make sure that the power plug on the rear of the device is always
accessible, so that the device can be disconnected from the power
supply.
Process
Next steps
Prerequisites
Power plug

Semi-Micro Osmometer K-7400S instructions, V3700
Unpacking and setup 13
To disconnect the device from the main power, disconnect the power
plug.
The osmometer needs a three-core power plug.
Electric shock
Danger of electric shock from damaged cables.
Make sure that the power cable is not subjected to high forces.
The power cable should not be bent or clamped.
Make sure that the power cable does not come in contact with liquids
and heat sources.

14
Semi-Micro Osmometer K-7400S instructions, V3700
6. Startup
Note: The device is not suitable for constant operation because it would
reduce the lifespan of the Peltier elements.
Skin injury
Risk of infection due to injuries caused by a contaminated stirring wire.
Wear protective gloves when handling the measuring head.
Skin injury
The cooling compartment reaches temperatures up to -30 °C during
the running measurement. Contact with unprotected hands may lead to
skin injuries.
Avoid direct contact with the cooling compartment.
Wear protective gloves.
Electronic defect
Damage to the electronics is possible if the device is switched on when
it is connected or disconnected from the power supply.
Switch o the device before pulling or plugging in the plug.
The device is switched o.
The power cable is detached from the power supply.
1. Attach the power cable to the power connector on the rear of the
device.
2. Switch the device on by using the „ON/ OFF“ switch.
Bring the device into operation. To put the device out of operation, switch
o the device and detach the power plug from the power supply.
Prerequisites
Procedure
Next steps

15
Semi-Micro Osmometer K-7400S instructions, V3700
7. Operation
7.1 Connecting the measuring head
Parts of the measuring head are an in-built motor with a stirring wire and
the thermistor as temperature sensor. The measuring head cable is to be
plugged into the connector on the back of the device.
The sample tube, filled with the exact volume of calibration or sample
solution (50–150µl) must be mounted onto the adapter.
Legend:
1
Stirring wire
2
Thermistor
3
Foot
Fig. 3:
3
21
Measuring head
Fig. 4: Sample tube

Semi-Micro Osmometer K-7400S instructions, V3700
Operation 16
Note: Any change of the measuring head causes the need for a precali-
bration of the device to adapt the device to the measuring head (see
„7.7.1 Pre-calibration“ on page 21).
The measuring head is placed on the housing plate with the sample tube
rising into the cooling cavity. The device is now ready for measurement.
Note: The sample volume can be reduced down to a volume of 50 µl. It
is important that all calibrations must be performed with exactly the same
volume as the later sample.
7.2 Standby position of measuring head
Note: Generally the measuring head should be stored with the attached
sample tube.
While working with the osmometer, use the four columns on top of the
device for temporarily set down the measuring head without sample
tube. In the measurement position, it is not necessary that the feet of the
measuring head rest on the device.
To avoid sample spilling into the measuring head, it must be held upright.
Fig. 5: Set-down of the measuring head without sample tube
7. 3 Measurement principle and process
The osmotic pressure in a solution is proportional to the freezing point
depression of that solution. An aqueous solution, with an osmotic pres-
sure corresponding to an ideal 1-molal solution, freezes at -1.858° C.
An aqueous solution with this freezing point has a concentration of
1Osmol/kg.

Semi-Micro Osmometer K-7400S instructions, V3700
Operation 17
To perform a measurement, the sample solution is cooled down first
without stirring. Even pure water can be super-cooled down to about -5
through -8° C without freezing. The freezing is initiated by an automati-
cally start of the stirring wire at a set temperature. The temperature rea-
ches the freezing point, 0° C in case of pure water (Fig. 6).
Fig. 6: Temperature-time-curve for pure water
The freezing point of a solution is below 0° C (Fig. 7). The freezing point
depression ΔT is a measure for the osmolality of a solution. It can be read
directly from the display given in mOsmol/kg.
Fig. 7: Temperature-time-curve for a sample solution
During a measurement, the actual temperature is displayed. The device
detects the maximum temperature reached, stores it, and if crystallization
occurred satisfactory, displays the result.

Semi-Micro Osmometer K-7400S instructions, V3700
Operation 18
After finishing the measurement, the sample tube is warmed up to 20 ° C
(standby temperature of the device). The measuring head can remain
there before and after measurement as long as desired.
7.4 Switch on
While switching on, the device performs an automatic self-test. During
this time, the display presents the start screen with the current firmware
version for a short time.
KNAUER V01.XX
Freezing Point Osmometer
After completion of the self-test, the display shows the measurement
screen (see Fig. 8 screen 1). The cursor is placed on the rhombus field. As
shown in Fig. 8, it will take you to the relevant menu points.
7.5 Menu guide
Starting with the cursor on the rhombus field, further menus become
accessible in an endless loop by pushing the vertical arrow buttons ÙÚ.
By pushing the horizontal arrow buttons Ø×, the cursor moves from field
to field. Only those fields are accessible which are allowed to change
the setting. Other fields, like the actual measured temperature, will be
skipped.
On any changeable field the possible settings can be scrolled using the
vertical arrow buttons ÙÚ. The displayed values will be accepted and sto-
red when leaving the field with one of the horizontal arrow buttons Ø×.
In this way, you can e.g. choose between printer and PC for data output
(screen 2) or display the measurement data in mOsmol or °C (screen 1).
Fig. 8: Menu path