BP100

Bubble Pressure Tensiometer

User Manual
V1-03

© KRÜSS GmbH, Hamburg 2008-2010

 Contents page 1

Contents

1 General Information ....................................................................................... 3

1.1 General safety information ................................................................................................. 3
1.2 Intended use ...................................................................................................................... 4
1.3 Reference to other manuals............................................................................................... 4
1.4 Procedure if repairs should be necessary .......................................................................... 4
1.5 Technical customer service................................................................................................ 5

2 Introduction .................................................................................................... 6

3 Setting up....................................................................................................... 8
3.1 Opening the transport packing and checking the scope of supply ..................................... 8
3.2 Transport............................................................................................................................ 8
3.3 Location and ambient conditions........................................................................................ 8
3.4 Levelling the unit ................................................................................................................ 9
3.5 Fitting the tempering vessel ............................................................................................... 9
3.6 Connectors and connections............................................................................................ 11

3.6.1 Power supply.............................................................................................................. 11

3.6.2 Connecting the BP100 Control Pad ........................................................................... 12
3.6.3 Interface connection ................................................................................................... 12
3.6.4 Connecting an external thermostat (optional)............................................................. 14
3.6.5 Fitting an external temperature measuring probe (optional)....................................... 14
3.6.6 Inert gas connector (optional)..................................................................................... 15

4 BP100 controls ............................................................................................ 16

4.1 The sample chamber ....................................................................................................... 16
4.2 The Control Pad............................................................................................................... 16

5 Operation and preparation for measurement .............................................. 18

5.1 Switching the BP100 on and off ....................................................................................... 18

5.1.1 Mains switch............................................................................................................... 18

5.1.2 On/Off key on the Control Pad ................................................................................... 18
5.1.3 Resetting the BP100 .................................................................................................. 18

5.2 Fitting a capillary .............................................................................................................. 19

5.3 Moving the sample platform ............................................................................................. 20

5.3.1 Moving the sample platform using the rotary knob..................................................... 21

5.3.2 Saving and activating standard sample platform positions......................................... 21

5.4 Setting up the sample vessel ........................................................................................... 22

 page 2 Contents

5.5 Stirring the sample ........................................................................................................... 22

5.6 Detecting the surface ....................................................................................................... 23
5.7 Immersing the capillary .................................................................................................... 23
5.8 Purging the capillary ........................................................................................................ 24
5.9 Illumination....................................................................................................................... 24

6 Cleaning and maintenance .......................................................................... 25

6.1 Cleaning the sample vessel ............................................................................................. 25

6.1.1 Step 1: Cleaning with water........................................................................................ 25

6.1.2 Step 2: Check cleanliness .......................................................................................... 25
6.1.3 Step 3 (if necessary): Scarfing ................................................................................... 25
6.1.4 Step 4 (if necessary): Cleaning with oxidising acid .................................................... 26

6.2 Cleaning the capillary....................................................................................................... 26

6.3 Checking capillaries ......................................................................................................... 27
6.4 Applying a hydrophobic coating (TO2031 silanising set).................................................. 28

6.4.1 Silanising reagent....................................................................................................... 28

6.4.2 Applying the coating ................................................................................................... 28
6.4.3 Regrinding the tip of a capillary .................................................................................. 29

6.5 Cleaning the surface of the BP100 .................................................................................. 30

7 Firmware update.......................................................................................... 31
7.1 Downloading current firmware ......................................................................................... 31
7.2 Loading the firmware........................................................................................................ 32

Appendix.......................................................................................................... 34

I Technical data ............................................................................................. 34

II Warranty and caveat emptor ....................................................................... 35

III Copyright and right to make alterations....................................................... 35

 General Information page 3

1 General Information

1.1 General safety information

As well as this general safety information, please follow the safety instructions in
the remainder of the manual text.

The BP100 is intended for use in a laboratory or pilot plant station. The general
safety rules for working in a laboratory environment apply to work carried out with
the BP100.

The BP100 may only be used by trained personnel.

When carrying out measurements with substances which are poisonous,

hazardous to health, irritant and/or easily inflammable, the safety regulations and, if
available, information in the appropriate safety data sheets must be taken into
account when handling such substances.

Do not use the BP100 in explosion-proof areas.

The controls of the BP100 and a connected computer must not be operated when
wearing protective gloves, which have already been used for handling hazardous
materials.

Do not use the BP100 if the unit is obviously damaged.

Disconnect the BP100 from the power supply immediately if there is any damage to
the electronics, if liquids are spilled over the BP100 or if there is an escape of
tempering medium.

! The BP100 has a motorised sample platform. Keep your hands away from the area
of movement while the platform is in motion. Make sure that no one is working
within the area of movement while the sample platform is moving. Do not place any
objects on the platform.
 page 4 General Information

1.2 Intended use

• The BP100 is intended exclusively for measuring the surface tension of liquids
using the bubble pressure method and the diameter of the capillaries used for this
method.

• Intended use includes the exclusive use of accessories supplied by KRÜSS or

substitutes with an identical design when disposable accessories are used.

• The BP100 can be used at ambient temperatures between 10°C and 40°C and with
air which is free from condensate.

• The tempering vessel of the BP100 can be used with tempering medium
temperatures between -10°C and 100°C.

1.3 Reference to other manuals

Ö The steps required for using the LabDesk software are described in the relevant
software manual.

1.4 Procedure if repairs should be necessary

Contact KRÜSS

 Contact KRÜSS customer support.

* If you did not obtain the measuring instrument directly from KRÜSS but from a
dealer, please contact your dealer first. He may be able to rectify the damage. If
not, contact KRÜSS customer support directly.

 You will be given a repair number. Please quote this number in your covering letter
when you dispatch the unit.

Send us the measuring instrument or accessories

! Do not dispatch the measuring instrument or accessories without consulting

KRÜSS customer support.

* Components which are not directly affected by the damage may also have to be
sent with the unit. KRÜSS customer support will advise you on the necessary
scope of the shipment.
 General Information page 5

! Remove liquids (e.g. samples, temperature control liquid) completely from the
instrument and the accessories.

! Clean the unit or accessories before dispatch. This applies particularly if there is
contamination due to hazardous substances.

! Use the original packaging to pack the instrument or accessories. If you no longer
have the original packaging, it must be ordered from KRÜSS at the customer’s
expense.

! Pack all components separately which were packed separately when the unit was
supplied. Do not dispatch the unit in the assembled state.

! If the instrument or accessories were provided with transportation locks, refit these
before shipping.

! Use box-in-box packaging.

* Our customer support department will be pleased to advise you regarding the
proper packaging.

1.5 Technical customer service

If problems should occur when working with the BP100 or with LabDesk, please
consult the technical customer support at KRÜSS GmbH. You can contact them at:

KRÜSS GmbH
Technical customer support
Tel:(+49) 040/514401-0
Fax:(+49) 040/514401-98
E-mail: info@kruss.de
 page 6 Introduction

2 Introduction

Dear KRÜSS GmbH Customer,

Thank you for purchasing the BP100 from KRÜSS.

Thanks to the simple handling of the unit, you will soon be carrying out your
measurements without any problems. However, we advise you to read this
documentation carefully before starting work and to follow the appropriate information
when installing the unit. As well as the instructions for use, you will also find helpful
information and tips, for example for the optimum preparation of a measurement.

! We strongly advise you not to carry out the installation and work without consulting
this manual.

* This manual is subject to a permanent quality control. The current version of the
manual can always be acquired from the download section of our homepage
www.kruss.de.

Possible options with BP100

The BP100 together with the LabDesk software gives you the following options:

• Measurement of dynamic surface tension as a function of surface age

• Measurement of dynamic surface tension at constant surface age

• Determination of the diameter of the capillary used

• Fit of surface-age-dependent surface tension according to Hua & Rosen

• Calculation of the diffusion coefficient according to Joos & Rillaerts

• Calculation of the adsorption coefficient according to Ward & Tordai

• Measurement at different sample temperatures

Introduction page 7

Measuring principle

Gas bubbles are produced in the liquid sample by means of a capillary which is
connected to a pressure sensor. To increase the size of such a bubble the pressure
must work against the surface tension of the liquid. The surface tension of the liquid
can be calculated from the maximum bubble pressure when the bubble is formed.

The time from the beginning of the formation of the bubble to the time that the
maximum pressure is detected is the age of the surface. In the case of the BP100, this
surface age can be specified over a wide measuring range. In this way, the surface
tension is measured as a function of surface age – information, which is important
particularly for assessing the dynamics of surfactants.

Ö You will find further information on the measuring principle and the theory behind
the bubble pressure method in the LabDesk software manual.
 page 8 Setting up

3 Setting up

3.1 Opening the transport packing and checking the scope of supply

 Open the transport packing Check the BP100 and its accessories for damage
during shipment.

! Please keep the transport packing material, at least the PE foam forms. The
transport packaging is required if the instrument has to be shipped for
reparation.

 Use the scope(s) of supply and the delivery note provided to check if the supply is
complete. Use the scope(s) of supply provided to check if the supply is complete.

 Please contact KRÜSS or your local dealer without delay if damage during
shipment occurred or if the supply is incomplete.

3.2 Transport

Remove any sample vessels from the sample platform before transporting.

! Two people are required for transporting the BP100.

 Transport the BP100 with the help of a trolley. Hold the unit firmly during
transportation.

 To lift the BP100 onto the trolley and from the trolley to the place of use: Hold from
both sides under the rear part of the baseplate. Support the unit from both sides by
holding under the recessed plate below the sample chamber.

3.3 Location and ambient conditions

For operational safety and accuracy of results the BP100 must be installed at an
adequate location.

When working with liquids which are volatile, toxic, irritant, hazardous to health
and/or inflammable: Locate the BP100 in a position which is designed for working
with the appropriate hazardous substances.

Set up the BP100 so that access to the mains connection is unrestricted and the
BP100 can be disconnected from the mains immediately in the event of danger.

• Set the unit up in a place where vibrations can be avoided.

 Setting up page 9

• Avoid large variations in room temperature during the measurements.

• Avoid contamination of the sample liquid by atmospheric air (e.g. by exhaust from
machines).

• Place the unit on a level, stable, and vibration-free base. Check if the base is level
using a bubble level or spirit level.

3.4 Levelling the unit

 Level the BP100 with the help of the two rear adjustable feet

and the spirit level fitted into the top of the BP100.

The air bubble in the spirit level must be completely within the inner circle.

3.5 Fitting the tempering vessel

Unplug the BP100 from the mains before assembly.

1. If you have ordered the optional TP0512 external temperature sensor:

2. Attach the temperature sensor bracket to the temperature vessel before fitting the
vessel (Ö P. 14).

3. Remove the screw fitted to the shaft of the tempering vessel (2.5 mm hexagon
socket wrench).
page 10 Setting up

4. Plug the multi-pin plug on the bottom of the tempering vessel into the socket on the
sample platform. Hold the vessel firmly and turn the coupling ring anticlockwise as
far as the stop.

5. Fix the shaft of the vessel to the angle bracket with the help of the previously
removed screw.

6. Slide the rubber sleeve over the shaft as far as the lower edge of the vessel.
 Setting up page 11

7. Connect the two Quick-Lock closures of the hoses coming from the tempering
vessel to the two sockets in the sample chamber.

3.6 Connectors and connections

3.6.1 Power supply

 Connect the mains plug supplied to a mains outlet (100-240 V AC).

 Connect the mains cable to the LINE connector on the back of the BP100.

! Use only the mains plug supplied with the BP100 (12 V, 2.5 A).
 page 12 Setting up

3.6.2 Connecting the BP100 Control Pad

Control Pad : Control keypad for manual control of the BP100.

 Connect the plug of the Control Pad to the CONTROL PAD connector on the back
of the BP100.

3.6.3 Interface connection

The BP100 can be connected to the computer via a serial or USB interface.

Serial interface

 Connect the SERIAL PC interface connector on the back of the BP100 to a

corresponding interface on the computer.

USB interface

 Connect the USB interface connector on the back of the BP100 to a corresponding
interface on the computer.
Setting up page 13

! When using a USB interface, two driver components must first be installed. The
drivers must always be installed when the BP100 is connected to a USB interface
for the first time.

1. Insert the LabDesk CD. Cancel the installation program if necessary.

2. Connect the USB interface connector on the back of the BP100 to a USB
connector on the computer. The operating system detects that a new hardware
component has been connected and starts the hardware assistant.

3. A prompt may appear as to whether

a driver is to be installed from the
Internet. Select the No, not this
time option. Click Next.

4. Select the Install the software

automatically option. Click Next.

5. The hardware assistant reports that

the installation was successful.
Click Finish .

6. The hardware assistant starts for a second time in order to install the other driver
file required. Repeat steps 3-5.
 page 14 Setting up

3.6.4 Connecting an external thermostat (optional)

 Connect the thermostat outlet to the Quick-Lock THERMOSTAT IN connector on

the back of the BP100.

 Connect the thermostat inlet to the Quick-Lock THERMOSTAT OUT connector on

the back of the BP100.

3.6.5 Fitting an external temperature measuring probe (optional)

1. Turn the tempering vessel over. Attach the bracket for the temperature sensor to
the underside of the tempering vessel with the help of the two screws supplied.

2. Fit the tempering vessel as described in Chapter 3.5.

3. Lift the flap of the temperature sensor connector in the measuring chamber.
Connect the sensor plug to the sensor connector.

* To read out the temperature of the external sensor when taking measurements:
Select the external option when defining the measurements on the Device tab
(Ö LabDesk manual).
 Setting up page 15

3.6.6 Inert gas connector (optional)

The gas flow for the bubble pressure measurement can also be produced with an
external inert gas feed instead of compressed air from the inbuilt compressor.

Use only inert gases such as nitrogen or argon. Do not use gases which are
harmful, poisonous, inflammable or corrosive.

! Use a pressure regulator and control the working pressure to a value of 1 to 2 bars.
The pressure measurement will no longer work reliably above 2 bars.

! The maximum pressure load is 5 bars. The unit may be damaged above this
pressure.
 Protect the inert gas feed with an overpressure valve which limits the pressure
to 5 bar.

 Connect the inert gas feed to the GAS connector on the back of the BP100.
 page 16 BP100 controls

4 BP100 controls

4.1 The sample chamber

Compressor
Lighting feed

Temperature Capillary
sensor

Tempering
vessel

Cables to and
from thermostat Sample
platform

4.2 The Control Pad

BP100 controls page 17

Control Pad functions

Control element Function

• Outer ring: Height controller for the sample platform.

Turn clockwise: Sample platform up.

Turn anticlockwise: Sample platform down.

* The amount of deflection determines the speed of

movement.

• Inner ring: Speed controller for stirrer.

• Switch BP100 on and off.

• Switch off the running compressor after purging

(PURGE).

Save and activate an upper and lower standard sample

platform position.

Switch purging for the capillary on and off.

Switch the stirrer on and off.

Initiate surface detection.

Switch sample chamber lighting on and off.

Immerse the capillary after detecting the surface

(immersion depth 10 mm).
 page 18 Operation and preparation for measurement

5 Operation and preparation for measurement

* When the operating steps described in this chapter have been completed,
measurements are carried out under software control.

Ö For information on defining and carrying out measurements, please read the
LabDesk manual.

5.1 Switching the BP100 on and off

5.1.1 Mains switch

 To connect and disconnect the BP100 from the mains: Use the Power switch on
the back of the housing.

5.1.2 On/Off key on the Control Pad

 To switch on the BP100: Press the

key.

The BP100 will be initialised. After about 5 seconds a double beep signal indicates
that the BP100 is ready for operation.

 To switch off the BP100: Press the same key for at least 2 seconds.

5.1.3 Resetting the BP100

 If the BP100 no longer responds to the Control Pad or LabDesk software:

 Press the RESET button on the back of the BP100.

 Operation and preparation for measurement page 19

5.2 Fitting a capillary

! Clean the capillary before fitting (Ö Chapter 6.2).

! Wear disposable gloves so that the capillary does not become contaminated.

! Take care not to damage the capillary when fitting and removing.

1. Undo the screw ring of the capillary holder.

2. Feed the capillary into the opening in the capillary holder against the slight
resistance as far as the stop.

3. Tighten the screw ring of the capillary holder until you feel a resistance.

! Do not overtighten the screw ring in order not to damage the capillary.
 page 20 Operation and preparation for measurement

Hydrophobic capillary coating

! Use only capillaries that have a hydrophobic coating. Capillaries can

• be obtained from KRÜSS already with a hydrophobic coating.

• be given a hydrophobic coating with the help of the TO2031 silanising kit
obtainable from KRÜSS (Ö Chapter 6.4).

! The hydrophobic coating must be renewed from time to time.

! After applying the hydrophobic coating the capillary diameter must be redetermined
(Ö LabDesk manual).

5.3 Moving the sample platform

Safety Instructions

Risk to personnel and material damage

When the sample table is lowered it is possible for limbs and objects under the sample
table to be crushed and under certain circumstances for the sample table itself to be
WARNING damaged. If the object in question is a vessel filled with a hazardous substance, this in
turn can lead to a risk due to the hazardous substance.

X Keep your hands away from the area of movement while the platform is in
motion. Make sure that no one is working within the area of movement while
the sample platform is moving.
X Do not place any objects on the BP100 platform.
X Before moving the sample platform, make sure that there are no objects on the
platform.

Risk of material damage

Sample vessels, which are raised when placed on the platform, can cause damage to
the capillary or vessel when moving the platform up.
CAUTION
X Place the sample vessel directly in the recess on the sample platform without
further increase in height.
 Operation and preparation for measurement page 21

5.3.1 Moving the sample platform using the rotary knob

 To raise the sample platform: Turn the rotary knob clockwise (in the Up direction).

 To lower the sample platform: Turn the rotary knob anticlockwise (in the Down
direction).

* The amount of deflection determines the speed of movement.

5.3.2 Saving and activating standard sample platform positions

Saving

1. Move to the required upper position of the sample platform using the rotary knob.

2. Press the key for about 2 seconds.

3. Move to the required lower position of the sample platform using the rotary knob.

4. Press the key for about 2 seconds.

* The arrows do not indicate the direction of movement. For example, when the
sample table is below the lower standard position, pressing the key initiates an
upward movement.

Activating

 To move the sample platform to the upper standard position:

Press the key briefly.

 To move the sample platform to the lower standard position:

Press the key briefly.

 page 22 Operation and preparation for measurement

5.4 Setting up the sample vessel

Ö For information on cleaning the sample vessel, please read Chapter 6.1

1. Fill the SV20 sample vessel with at least 69 ml of the sample liquid.

* If you are using a different sample vessel: Enter the dimensions of the vessel
used when defining the measurements in LabDesk (Ö LabDesk manual). The
minimum filling volume will be specified when starting a measurement.

2. Lower the sample platform sufficiently to enable you to position the sample bowl
without damaging the capillary.

3. Place the sample vessel in the recess in the sample platform.

4. Immerse the tip of the external temperature measuring probe in the liquid if
necessary.

5. Raise the sample platform so that the tip of the capillary is immediately above the
surface.

5.5 Stirring the sample

 Place a clean magnetic stirring rod in the sample bowl.

 Switch on the stirrer with the

key. To switch the stirrer off again: Press the same key a second time.

! The stirrer must be switched off during a measurement. Also, wait until the liquid is
still before carrying out the measurement.

* Stirring can also be carried out under software control if the measurement is
defined accordingly in LabDesk.

Stirring speed

When the stirrer is running, the stirring speed can be controlled with the help of the
inner rotary knob on the Control Pad.
 Operation and preparation for measurement page 23

5.6 Detecting the surface

* The surface can also be detected under software control instead of with the Control
Pad (Ö LabDesk manual).

 Close the doors of the measuring chamber.

 Press the

key.

The sample platform will rise until contact with the capillary is registered.

* The surface is detected with the default settings of speed and sensitivity as set
in LabDesk. If other parameters are used, detection must be carried out with
LabDesk using the required parameters (Ö LabDesk manual).

5.7 Immersing the capillary

* The immersion of the capillary can also be carried out under software control
instead of with the Control Pad (Ö LabDesk manual)

* The immersion process will not be started if the capillary contains liquid or is
already immersed.

 Press the

key.

The capillary will be immersed.

* Immersion takes place with the default settings of speed and sensitivity as set
in LabDesk. If other parameters are used, immersion must be carried out using
the required parameters (Ö LabDesk manual).
 page 24 Operation and preparation for measurement

5.8 Purging the capillary

As a result of the capillary force there will be liquid in the capillary following a
measurement. This must be removed before the next measurement by purging the
capillary with air.

 Press the

key.

The compressor will be switched on.

* Once it is switched on, the compressor does not switch off again completely

even when the key is pressed for a second time. The continuous flow of air
ensures that no further liquid can get into the capillary.

 To switch off the compressor: Press the key briefly.

* The capillary can also be purged automatically if the measurement is defined

accordingly in LabDesk (Ö LabDesk manual).

5.9 Illumination

When the BP100 is switched on, the illumination is also initially switched on.

 To switch the illumination off or on again: Press the key.

 Cleaning and maintenance page 25

6 Cleaning and maintenance

6.1 Cleaning the sample vessel

The first two cleaning steps should also be carried out before a sample vessel is used
for the first time.

! Do not use cleaning agents which contain surfactants (soap, rinsing agents) or any
alkaline cleaning agents.

! Use only pure solvent and clean, lint-free cloths.

6.1.1 Step 1: Cleaning with water

 Rinse out the sample vessel under hot flowing water, wiping it alternately with
paper.

 Rinse the sample vessel with distilled water.

6.1.2 Step 2: Check cleanliness

 Wipe out the sample vessel with moistened tissue paper.

• If there is a squeaking sound when wiping, the sample vessel is clean. Rinse
the sample vessel again with distilled water. Dry the sample vessel in a drying
cabinet.

• If the paper slides on the glass, there are surface-active substances on the
surface of the glass. In this case, carry out more intensive cleaning by
performing the step described below.

6.1.3 Step 3 (if necessary): Scarfing

 Scarf the sample vessel with the flame of a Bunsen burner.

When scarfing use crucible tongs and wear fire-proof gloves.

Allow the glass to cool on a heat-resistant sheet before using it again.

 page 26 Cleaning and maintenance

Risk of injury due to shattering glass

If the glass should shatter, slivers of glass may cause injury.

X Scarf the glass slowly and evenly. Do not allow it to glow red-hot.
WARNING
X Allow the glass to cool before rinsing with water.
X Wear sound laboratory clothing and safety goggles.

6.1.4 Step 4 (if necessary): Cleaning with oxidising acid

 Only in the case of contamination which has not been removed using the previous
measures: Clean the glass with a concentrated oxidising acid.

This work must only be carried out by persons who are familiar with the dangers
involved when handling acids and who are familiar with the necessary safety
procedures. Acquaint yourself with the properties of the substances used. Pay
attention to the appropriate R and S phrases (safety advice).

6.2 Cleaning the capillary

1. After the measurement rinse the capillary through with pure water with the help of a
spray bottle.

2. Rinse the capillary through in the same way with a pure, water-soluble and
degreasing solvent.

3. Dry the capillary in a drying cabinet at a maximum temperature of 70°C.

 Cleaning and maintenance page 27

6.3 Checking capillaries

Capillaries must be hydrophobic on the inside and hydrophilic on the outside at the tip
and must be free from nicks or signs of glass abrasion.

* The hydrophobic coating of capillaries wears away with time. When this wear
becomes noticeable depends on the samples, the sample throughput and the
measurement conditions.

 Initially carry out measurements several times a week with pure water in a surface
age range of 10 to 1000 ms in order to check the capillaries. Increase the time
between test measurements if capillaries are intact for longer under the given
measuring conditions.

Criteria for assessing a capillary

• Steady-state measured value for water: The measured values for pure water
without surface-active substances should be essentially independent of the bubble
age. The values for the smaller bubble ages in the specified range should not
deviate from the steady-state value by more than 1 mN/m.

• Stepless curve: The curve for the water measurement, and also that of a pure
surfactant solution, should not exhibit any steps or kinks. These are a sign of a
hydrophilic inner wall or a hydrophobic capillary tip (insufficiently ground after
applying the hydrophobic coating).

Several steps in a curve are often the result of glass abrasion or a nicked capillary
tip.

Measures

 If one of the deviations described above occurs: Grind the tip of the capillary
(Ö Chapter 6.4.3) and repeat the test measurement.

 If the problem still persists: Carry out the coating procedure described in Chapter
6.4 or replace the capillary with a hydrophobically coated capillary obtained from
KRÜSS.

 With very irregular curves or when measurements with the capillary have not been
improved after carrying out the previous steps: View the tip of the capillary under a
microscope. If nicks can be seen: Replace the capillary with a new one.
 page 28 Cleaning and maintenance

6.4 Applying a hydrophobic coating (TO2031 silanising set)

* When capillaries are not hydrophobic, a film of liquid remains after the rinsing
process. This film leads to unclean bubble formation and consequently to
measuring errors. This effect is prevented by applying a hydrophobic coating to the
inner wall of the capillary with the help of a silanising reagent.

! The hydrophobic layer is unstable in the presence of medium strength and strong
acids (under pH 5). When making measurements in weak acids (down to pH 5) the
coating process must be carried out more frequently.

6.4.1 Silanising reagent

For applying a hydrophobic coating to the capillary you will need a silanising reagent.

* KRÜSS recommends “Silanization Solution I” from Fluka (5% solution of dimethyl-

dichlorosilane in heptane).

Risk of fire / Risk due to irritant liquid and vapours

The suggested reagent is easily inflammable and irritates the eyes, respiratory organs
and skin. The reagent reacts with water to form irritant gasses.

X Work with the silanising reagent must only be carried out by personnel who
WARNING have been trained in the handling of hazardous substances.
X Follow the safety instructions on the chemical container and the safety data
sheet. Pay attention to the appropriate R and S phrases (safety advice).

6.4.2 Applying the coating

1. Remove the capillaries (maximum five) from the protective transport sleeves.

2. Place the capillaries with the tip down in the holes of the capillary holder.
 Cleaning and maintenance page 29

3. Pour about 25 ml of the silanising reagent into a 50 ml glass beaker.

4. Place the capillary holder carefully on the beaker. Approximately the lower third of
the capillaries should now be immersed.

5. Leave the capillaries in the reagent for between 6 and 12 hours.

! The heptane may evaporate completely if allowed to stand for longer. This will
then obviate the hydrophobic coating effect of the treatment.

6. Dispose of the used silanising reagent in accordance with the manufacturer’s

instructions.

7. Thoroughly rinse the capillaries individually with the help of a spray bottle using a
pure degreasing solvent.

8. Dry the capillaries in a drying cabinet at a maximum temperature of 70°C.

6.4.3 Regrinding the tip of a capillary

* The hydrophobic coating necessary for the inner wall of the capillary has a
disruptive effect on the outside of the tip. The tip must therefore be reground using
the grinding kit belonging to the TO2031 silanising set.

1. Moisten the abrasive paper attached to the grinding block with a little water.

! Do not use dry abrasive paper for grinding capillaries as this can damage them.

2. Draw the tip of the capillary two or three times over the abrasive paper while
applying slight pressure.

3. With the help of a spray bottle thoroughly rinse the capillary with acetone in order to
remove any possible grinding residue from the inside of the capillary.

4. Dry the capillary in a drying cabinet at a maximum temperature of 70°C.

! After coating and grinding, the capillary diameter must be redetermined

(Ö LabDesk manual).
 page 30 Cleaning and maintenance

Changing the abrasive paper

When the abrasive paper is worn it must be changed.

1. Remove the worn abrasive paper from the grinding block.

2. Take a new sheet of abrasive paper from the silanising set. Remove the protective
foil.

3. Stick the abrasive paper to the grinding block.

6.5 Cleaning the surface of the BP100

 Use soft cloths, which will not scratch the stainless steel surface, for cleaning the
BP100.

 Clean the surface of the BP100 with pure water and a little rinsing agent if
necessary.

 For the stainless steel surfaces: Remove dirt that is insoluble in water with a
suitable solvent (e.g. isopropanol).

! The painted surfaces of the BP100 can become dull due to contact with organic
solvents.
 Firmware update page 31

7 Firmware update

When a firmware update becomes available, this can be downloaded from our website
www.kruss.de and loaded onto the BP100.

7.1 Downloading current firmware

1. Go to our website www.kruss.de. Click on Login.

2. Enter your Username and Password. Click on Login.

* You should have received the user name and password by e-mail shortly after
delivery of the BP100. If you do not have this information, please register using
the link Please register for a user account and follow the instructions.
 page 32 Firmware update

3. Click on Download.

4. Click on Software Updates.

5. Under BP100, download the ZIP archive with the filename that indicates the
highest firmware number.

6. Click on Log-Out.

7.2 Loading the firmware

1. Extract the downloaded archive.

! All files of the extracted archive must be in the same folder in order to load the
firmware.

2. Connect the RS-232 or USB interface connector on the back of the BP100 to a
corresponding interface on the computer.

3. Switch on the BP100. Wait until the BP100 has initialised.

Firmware update page 33

4. Start the UPLOADER.EXE program, which will be found amongst the extracted
files.

5. Enter the number of the interface used. Press Enter.

* An incorrect interface number can give rise to two different events:

• When the selected interface exists but the device is not connected to it: The
update program tries to establish contact with the device via the specified
interface. The Scanning Nodes message appears. A value will be counted
up.

After this, the upload program will be terminated without any further
message.

• y When the selected interface does not exist: The following error message
appears:

The upload program will be terminated after confirming with OK .

6. If the device is properly connected and the port has been entered correctly, the
firmware will begin to load after a few seconds.

7. When the process is complete, a double beep indicates that the BP100 has been
initialised. The BP100 is ready for use.
 page 34 Appendix

Appendix

I Technical data

Measuring range

SFT1 10 to 100 mN/m

Temperature: -10 to 100°C

Reading accuracy

SFT: ± 0.01 mN/m

Temperature: ± 0.01°C

Surface age1: 5 ms – 200s

Others

Data output: USB, RS232C

Power consumption: max. 30 W

Mains voltage: 100-240 V AC; 47 – 63 Hz

Operating voltage/ 12V, 2.5 A /

Polarity

Weight: 15 kg

Dimensions: 300 X 540 X 320 mm (W X H X L)

1 Dependent on the capillaries and liquid used

 Appendix page 35

II Warranty and caveat emptor

The warranty terms and deadlines are described in the general terms and conditions of
KRÜSS GmbH.

There is no warranty claim if the product was damaged due to careless usage or
improper treatment or if it was not used according to purpose, and if the instructions
and danger warnings in the manual were not observed.

The warranty claim is void if changes on the product are performed by the customer or
a third party without prior consultation of KRÜSS GmbH, which go beyond the activities
described in the manual. This also applies to repair work, which was independently
performed or carried out by a third party.

III Copyright and right to make alterations

The information contained in this document may be altered without notice and does not
represent any obligation by KRÜSS GmbH.

Neither this manual nor any part of it may be reproduced or transmitted for any
purpose whatsoever in any form and by any means, electronic or mechanical, by
photocopy or drawing without the express approval of KRÜSS GmbH in writing.

© 2008-2010, KRÜSS GmbH, Hamburg, all rights reserved.