KERN ACS-A03 User manual

KERN & Sohn GmbH
Ziegelei 1
D-72336 Balingen
E-Mail: [e-mail]
Phone: +49-[0]7433- 9933-0
Fax: +49-[0]7433-9933-149
Internet: www.kern-sohn.com
Operating instructions
Set for Density determination for
Analytical Balances KERN ACJ / ACS
KERN ACS-A03
Version 1.0
04/2012
GB
ACS-A03-BA-e-1210

2 ACS-A03-BA-e-1210
GB
KERN ACS-A03
Version 1.0 04/2012
Operating instructions
Density Determination Set for Analytical Balances
KERN ACJ / ACS
Contents:
1INTRODUCTION.................................................................................................................................3
1.1 SCOPE OF DELIVERY..................................................................................................................3
2PRINCIPLE OF DENSITY DETERMINATION ...................................................................................5
2.1 INFLUENCING MAGNITUDES AND ERROR SOURCES.......................................................................6
3INSTALLING THE DENSITY DETERMINATION SET.......................................................................7
4DENSITY DETERMINATION OF SOLIDS .........................................................................................9
4.1 ACTIVATE "DENSITY DETERMINATION SOLID MATTER"MODE .........................................................9
4.2 CALCULATE DENSITY ...............................................................................................................11
4.3 DENSITY DETERMINATION OF SOLID MATERIAL WITH A DENSITY OF LESS THAN 1G/CM3................12
5DETERMINING DENSITY OF LIQUIDS...........................................................................................13
5.1 DETERMINE VOLUME OF THE GLASS SINKER ..............................................................................13
5.2 CALL UP "DENSITY DETERMINATION FLUID"................................................................................14
5.3 CALCULATE DENSITY ...............................................................................................................15
6DATA-HOLD FUNCTION .................................................................................................................16
6.1 ACTIVATE FUNCTION................................................................................................................16
6.2 HOLD /DELETE RESULT OF DENSITY DETERMINATION ON DISPLAY...............................................16
7PRECONDITIONS FOR PRECISE MEASUREMENTS................................................................17
7.1 CALCULATION OF RESULTS......................................................................................................17
7.2 INFLUENCE FACTORS FOR MEASUREMENT ERRORS ..................................................................17
7.2.1 Air bubbles........................................................................................................................17
7.2.2 Solid matter sample..........................................................................................................17
7.2.3 Liquids...............................................................................................................................18
7.2.4 Surface..............................................................................................................................18
7.3 GENERAL INFORMATION...........................................................................................................18
7.3.1 Density / Relative Density.................................................................................................18
7.3.2 Drift of Balance Display ....................................................................................................18
8DENSITY TABLE FOR FLUIDS....................................................................................................19
9MEASUREMENT UNCERTAINTY DURING DENSITY DETERMINATION OF SOLID MATTER20
10 USER INSTRUCTIONS.................................................................................................................21

ACS-A03-BA-e-1210 3
1 Introduction
•In order to guarantee a safe and trouble-free operation, please
read carefully the operating instructions.
•These operating instructions only describe the operation of the
density determination set. For further information on how to
operate your balance please refer to the operating instructions
supplied with each balance.
1.1 Scope of delivery
Check packaging and density determination set immediately when unpacking for
possible visible damage.
Make sure that all parts are completely present.
Fig. 1 Scope of delivery
No. Description Number
(1) -1 Immersion basket for descending solid matter (density> 1 g/cm³) 1
(1) -2 Immersion basket forfloating solid matter (density < 1 g/cm³) 1
(2) Weighing tray holder 1
(3) Glass container ∅90 mm, h = 60 mm 1
(4) Platform for glass container 1
(5)
Thermometer
1
(5) -1 Rubber stop for thermometer 1
(6) Holder for thermometer 1
(7) Glass sinker 1
Operating instructions 1
(7)

4 ACS-A03-BA-e-1210
Fig. 2: Installed density set KERN ACS-A03
Fig. 3: Immersion basket for solid matter
A Upper sample dish (weight of the sample in air)
B Lower sample dish (weight of the sample in measuring liquid)

ACS-A03-BA-e-1210 5
ρ =
A
A-B o
ρ
ρ = m
V
2 Principle of Density Determination
Three physical magnitudes are the volume and the mass of bodies as well as the
density of matter. In density mass and volume are related.
Density [ ρ] is the relation of mass [ m ] to volume [ V ].
SI-unit of density is kilogram divided by cubic meter (kg/m³). 1 kg/m³ equals the
density of a homogenous body that, for a mass of 1 kg, has the volume of 1 m³.
Additional frequently applied units include:
, ,
The application of this density determination set in combination with the KERN
ABS/ABJ balances provides fast and safe determination of solids and fluids. Our set
uses the "Principle of Archimedes" to determine density:
BUOYANCY IS A FORCE. IT AFFECTS A BODY THAT IS IMMERSED INTO A FLUID. THE
BUOYANCY OF THE BODY EQUALS THE WEIGHT FORCE OF THE DISPLACED FLUID. THE
FORCE OF BUOYANCY ACTS VERTICALLY UPWARDS.
Thus, density is calculated according to the formulae below:
To determine the density of solid matter
Our balances enable weighing of solids in air [ A ] as well as water [ B ]. If the density
of the buoyancy medium is known [ ρo ] the density of the solid [ ρ] is calculated as
follows:
ρ= density of sample
A = weight of the sample in air
B = weight of sample in measuring fluid
ρo = density of measuring fluid
1g
cm3
1kg
m3
1g
l

6 ACS-A03-BA-e-1210
ρ = V
A-B
Determining density of liquids
The density of a fluid is determined with the help of a sinker providing a known
volume [ V ]. The sinker is weighed in air [ A ] as well as in the sample fluid [ B ].
According to the Archimedes’ Principle a body immersed in a fluid experiences a
force of buoyancy. [ G ]. This force equals the weight force of the fluid displaced by
the volume of the body.
The volume [ V ] of the immersed body equals the volume of the displaced fluid.
G = buoyancy of sinker
Buoyancy of sinker =
Weight of the sinker in air [ A ] -weight sinker in sample liquid [ B ]
From this follows:
ρ= density of sample fluid
A = weight of sinker in air
B = weight of sinker in sample fluid
V = volume of sinker*
* If the volume of the sinker is unknown, this can be determined by a solid body
density measurement e.g. in water and be calculated as follows.
V = volume of sinker
A = weight of sinker in air
B = weight of sinker in water
ρW = density of water
2.1 Influencing magnitudes and error sources
Air pressure
Temperature
Volume deviation of the sinker
Surface tension of the liquid
Air bubbles
Immersion depth of the sample dish of sinker
Porosity of the solid

ACS-A03-BA-e-1210 7
3 Installing the density determination set
•If necessary, carry out necessary adjustment before installation of the density
set.
•When the density set is installed, correct adjustment is not possible.
•For reasons of adjustment, take away the density set and place the standard
weighing plate.
1. Switch off balance and separate it from the power supply.
2. Remove standard weighing plate,
screening ring and weighing plate
carrier.
3. Insert balance tray holder
carefully
4. Place the platform for glass
containers in a way that it does not
touch the balance tray holder.
5. Mount the immersion basket; ensure
that it hangs centrically in the recess
of the weighing tray holder.

8 ACS-A03-BA-e-1210
6. Close the glass doors. Connect
balance to power supply, the balance
will carry out a self-test. The balances
of the ACJ series also carry out an
adjustment with the internal
adjustment weight.
Wait until “off“ appears.
7. Press the ON/OFF key, the gram
display will appear.
8. Fix the thermometer according to the
illustration on the glass container. Fill
the glass container with auxiliary or
sample fluid.
9. Take away the immersion basket and put the glass container in the center of the
platform.
10.Remount the immersion basket. Make sure that it does not touch the glass
container.
11.Heat the liquid, the instruments or the sinker until the temperature is constant.
Observe the warm-up time of the balance.

ACS-A03-BA-e-1210 9
4 Density determination of solids
for the density determination of solid material, the solid is weighed first in air and then
in the auxiliary liquid. From the weight difference results the buoyancy from where
the software calculates the density.
4.1 Activate "density determination solid matter" mode
1. Call up menu:
In weighing mode press the MENU button
twice
2. Press the navigation buttons ()
repeatedly until „APL.FUNC“ is displayed.
3. Press PRINT
4. Press the navigation buttons ()
repeatedly until „SG“ is displayed. To
confirm, press TARE, "SET" followed by your
current setting will be displayed.
5. Press the cursor keys () repeatedly until
“S.SG“ ("density determination solid matter")
is displayed.
Confirm with TARE. "SET" followed by the
currently set auxiliary fluid will be displayed.
6. Press the cursor keys () repeatedly until
the desired auxiliary fluid is displayed.
Display Auxiliary fluid
Destilled water
Ethyl alcohol
Methyl alcohol
To use a different auxiliary fluid of your choice, select "OTHER".
To confirm, press TARE, "SET" followed by the display used to enter
"temperature auxiliary fluid" will appear.

10 ACS-A03-BA-e-1210
7. Press TARE and the display will change to
numeric data input.
The temperature currently set will be
displayed if water, ethanol or methanol is
selected.
On selecting "OTHER" the currently set
density of the fluid
Either
When selecting water, ethanol or methanol,
read the temperature at the thermometer or
enter it, using the cursor keys.
or
When selecting "OTHER" enter density of
auxiliary fluid of your choice.
Numeric input
#
indicates that the weighing balance is in
numeric input mode. The first digit is
flashing and can be changed.
Increase flashing digit
Decrease flashing digit
Digit selection to the right
Confirm entry
8. The weighing balance will display the
auxiliary fluid’s density at the entered
temperature for about 3 sec and will then
change to "density determination solid
matter" mode.

To change from density mode to weighing mode press MENU for 3 s.