KERN EFS Series User manual

KERN & Sohn GmbH
www.kern-sohn.com
Ziegelei 1
72336 Balingen-Frommern
Germany
+0049-[0]7433-9933-0
+0049-[0]7433-9933-149
[e-mail]
Operating instructions
Precision balance
KERN EFS
Type TEFS-A
Version 1.1
2022-04
GB
EFS-BA-e-2211

EFS-BA-e-2211
2
GB
KERN EFS
Version 1.12022-04
Operating instructions - Precision Balance
Contents
1Technical data................................................................................................ 3
2Basic Information (General).......................................................................... 5
2.1 Proper use................................................................................................................. 5
2.2 Improper Use............................................................................................................. 5
2.3 Warranty.................................................................................................................... 5
2.4 Monitoring of Test Equipment.................................................................................... 6
3Basic Safety Precautions.............................................................................. 6
3.1 Pay attention to the instructions in the Operation Manual .......................................... 6
3.2 Personnel training...................................................................................................... 6
4Transport and storage................................................................................... 6
4.1 Testing upon acceptance........................................................................................... 6
4.2 Packaging / return transport....................................................................................... 6
5Unpacking, Installation and Commissioning............................................... 7
5.1 Installation Site, Location of Use................................................................................ 7
5.2 Unpacking and checking............................................................................................ 8
5.2.1 Placing........................................................................................................................................ 8
5.2.2 Scope of delivery........................................................................................................................ 8
5.2.3 Stackability ................................................................................................................................. 8
5.3 Overview of displays.................................................................................................. 9
5.4 Keyboard overview .................................................................................................... 9
5.5 Battery operation (Standard).....................................................................................10
5.6 Mains connection (option).........................................................................................10
5.7 Initial Commissioning................................................................................................10
5.8 Adjustment................................................................................................................11
6Operation...................................................................................................... 12
6.1 Weighing...................................................................................................................12
6.2 Taring .......................................................................................................................12
6.3 Weighing Units..........................................................................................................13
7Menu ............................................................................................................. 13
7.1 Navigation in the menu.............................................................................................13
7.2 Menu overview..........................................................................................................14
7.3 Description of individual menu items.........................................................................14
7.3.1 Weighing units switch-over....................................................................................................... 14
7.3.2 Zero tracking............................................................................................................................. 14
7.3.3 AUTO-OFF function.................................................................................................................. 15
7.3.4 Reset function........................................................................................................................... 16
8Servicing, maintenance, disposal .............................................................. 16
8.1 Cleaning ...................................................................................................................16
8.2 Servicing, maintenance.............................................................................................16
8.3 Disposal....................................................................................................................16
9Instant help for troubleshooting................................................................. 17
10 Declaration of conformity ........................................................................... 18

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1 Technical data
KERN EFS 200-1 EFS 500-2 EFS 600-1
Type/Article number TEFS 220-1-A TEFS 500-2-A TEFS 620-1-A
Readability (d) 0.1 g 0.01 g 0.1 g
Weighing range (max) 220 g 500 g 620 g
Reproducibility 0.2 g 0.02 g 0.2 g
Linearity ± 0.3 g ± 0.03 g ± 0.3 g
Recommended adjustment
weight, not added (class) 200 g
(M1)
500 g
(F2)
500 g
(M2)
Stabilization time (typical) 2-3 sec.
AUTO-OFF-function
(With battery operation)
OFF, 30 sec, 1 min, 3 min.
Units dwt, g, gn, oz, ozt, lb
Operating temperature +10°C… +40°C
Humidity of air max. 80 % (not condensing)
Housing (B x D x H) mm 145 x 205 x 45
Weighing plate mm 134 x 127
Battery operation (Standard) 4 x 1.5 V AA
Operating period: 200 h
Mains adapter (optional) 6 V / 1 A

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KERN EFS 2000-0 EFS 3000-1 EFS 5000-0
Type/Article number TEFS 2200-0-A TEFS 3000-1-A TEFS 5200-0-A
Readability (d) 1 g 0.1 g 1 g
Weighing range (max) 2200 g 3000 g 5200 g
Reproducibility 2 g 0.2 g 2 g
Linearity ± 3 g ± 0.3 g ± 3 g
Recommended adjustment
weight, not added (class) 2000 g
(M1)
3000 g
(F2)
5000 g
(M1)
Stabilization time (typical) 2-3 sec.
AUTO-OFF-function
(with battery operation)
OFF, 30 sec, 1 min, 3 min.
Units dwt, g, gn, oz, ozt, lb
Operating temperature +10°C… +40°C
Humidity of air max. 80 % (not condensing)
Housing (B x D x H) mm 145 x 205 x 45
Weighing plate mm 134 x 127
Battery operation (Standard) 4 x 1.5 V AA
Operating period: 200 h
Mains adapter (optional) 6 V / 1 A

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2 Basic Information (General)
2.1 Proper use
The balance you purchased is intended to determine the weighing value of material to
be weighed. It is intended to be used as a “non-automatic balance”, i.e. the material to
be weighed is manually and carefully placed in the centre of the weighing pan. As soon
as a stable weighing value is reached, the weighing value can be read.
2.2 Improper Use
Do not use balance for dynamic weighing. In the event that small quantities are
removed or added to the material to be weighed, incorrect weighing results can be
displayed due to the “stability compensation“. (Example: Slowly draining fluids from a
container on the balance.)
Do not leave permanent load on the weighing pan. This may damage the measuring
system.
Impacts and overloading exceeding the stated maximum load (max) of the balance,
minus a possibly existing tare load, must be strictly avoided. Balance may be damage
by this.
Never operate balance in explosive environment. The serial version is not explosion
protected.
The structure of the balance may not be modified. This may lead to incorrect weighing
results, safety-related faults and destruction of the balance.
The balance may only be used according to the described conditions. Other areas of
use must be released by KERN in writing.
2.3 Warranty
Warranty claims shall be voided in case:
- Our conditions in the operation manual are ignored
- The appliance is used outside the described uses
- The appliance is modified or opened
- Mechanical damage and damage caused by media, liquids
- Natural wear and tear
- The appliance is improperly installed or incorrectly electrically connected
- The measuring system is overloaded

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2.4 Monitoring of Test Equipment
In the framework of quality assurance the measuring-related properties of the balance
and, if applicable, the testing weight, must be checked regularly. The responsible user
must define a suitable interval as well as type and scope of this test. Information is
available on KERN’s home page (www.kern-sohn.com with regard to the monitoring of
balance test equipment and the test weights required for this. In KERN’s accredited
DKD calibration laboratory test weights and balances may be calibrated (return to the
national standard) fast and at moderate cost.
3 Basic Safety Precautions
3.1 Pay attention to the instructions in the Operation Manual
Carefully read this operation manual before setup and
commissioning, even if you are already familiar with KERN balances.
3.2 Personnel training
The appliance may only be operated and maintained by trained staff.
4 Transport and storage
4.1 Testing upon acceptance
When receiving the appliance, please checkpackaging immediately, andthe appliance
itself when unpacking for possible visible damage.
4.2 Packaging / return transport
Keep all parts of the original packaging for a possibly required
return.
Only use original packaging for returning.
Prior to dispatch disconnect all cables and put aside loose/mobile
parts.
Reattach possibly supplied transport securing devices.
Secure all parts such as the glass wind screen, the weighing
platform, power unit etc. against shifting and damage.

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5 Unpacking, Installation and Commissioning
5.1 Installation Site, Location of Use
The balances are designed in a way that reliable weighing results are achieved in
common conditions of use.
You will work accurately and fast, if you select the right location for your balance.
Therefore, observe the following for the installation site:
•Place the balance on a firm, level surface;
•Avoid extreme heat as well as temperature fluctuation caused by
installing next to a radiator or in the direct sunlight;
•Protect the balance against direct draughts due to open windows and
doors;
•Avoid jarring during weighing;
•Protect the balance against high humidity, vapours and dust;
•Do not expose the device to extreme dampness for longer periods of
time. Non-permitted condensation (condensation of air humidity on the
appliance) may occur if a cold appliance is taken to a considerably
warmer environment. In this case, acclimatize the disconnected
appliance for ca. 2 hours at room temperature.
•Avoid static charging of the material to be weighed, weighing container
and windshield.
If electro-magnetic fields or static charge occur, or if the power supply is unstable,
major deviations on the display (incorrect weighing results) are possible. In that case,
the location must be changed.

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5.2 Unpacking and checking
Remove the device and the accessories from the packaging, remove the packaging
material and place the device on the allocated work place. Check if that there has been
no damage and that all items of delivery scope are present.
5.2.1 Placing
The balance must be installed in a way that the weighing plate is exactly in horizontal
position.
5.2.2 Scope of delivery
Serial accessories:
KERN EFS
•Balance
•Batteries (4 x 1.5V AA)
•Operating instructions
5.2.3 Stackability
There is a possibility to stack up to 5 scales on top of each other

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5.3 Overview of displays
1
Battery display
2
Bar graph
3
Net weight
4
Negative value
5
Balance set at zero
6
Stability display
7
Weighing Units
5.4 Keyboard overview
•Switch-on balance (press button shortly)
•Switch off balance (press button long time)
•
In menu
: Confirm menu item
•Tare/set on zero the balance
•Menu access (press button long time)
•
In menu
: Select menu items

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5.5 Battery operation (Standard)
Remove the battery cover under the weighing pan. Insert 4 x 1.5 V batteries. Reinsert
the battery cover.
In order to save the battery, the balance switches automatically off after 3 minutes
without weighing.
•If the batteries are approximately exhausted, the battery symbol appears on the
display.
•If the batteries are completely exhausted, the battery symbol and „Lo bAt“
appear on the display.
•Press button and change batteries immediately.
If the balance is not used for a longer time, take out the batteries and store them
separately. Leaking battery liquid could damage the balance.
5.6 Mains connection (option)
Power is supplied via the external mains adapter KERN YKA-27 (optional). The
stated voltage value must be the same as the local voltage.
Only use original KERN mains adapters. Using other makes requires consent by
KERN.
5.7 Initial Commissioning
A warming up time of 3 minutes after switching on stabilizes the measuring values.
The accuracy of the balance depends on the local acceleration of gravity.
Strictly observe hints in chapter “Adjustment”.

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5.8 Adjustment
As the acceleration value due to gravity is not the same at every location on earth,
each balance must be coordinated - in compliance with the underlying physical
weighing principle - to the existing acceleration due to gravity at its place of location
(only if the balance has not already been adjusted to the location in the factory). This
adjustment process must be carried out for the first commissioning, after each
change of location as well as in case of fluctuating environment temperature. To
receive accurate measuring values it is also recommended to adjust the balance
periodically in weighing operation.
With an adjustment weight, the weighing accuracy can be checked and re-adjusted at
any time.
Procedure when adjusting:
Observe stable environmental conditions. Stabilisation requires a certain warm-up
time.
Start balance by
Press long time until „unit“ appears.
Press again, „cALE“ appears
Press
, “Zero” followed by the required adjustment
weight, will appear
(example)
After that „PutLd“ is displayed.
Place adjustment weight. „Wait“,
followed by „reMLd“ is
displayed.
During the display „rEMld“ take away the
adjustment weight.
The balance changes automatically into weighing mode.
Adjustment has now been completed successfully.
If an adjustment error occurs or a wrong adjustment weight is placed, „WronG“ is
displayed. Repeat adjustment.
Keep the adjustment weight close to the balance. Daily control of the weighing
exactness is recommended for quality-relevant applications.

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6 Operation
6.1 Weighing
Start balance by pressing
. The balance carries out a
selftest and then changes to the zero display.
If the weighed material is heavier than the weighing range,
in the display appears (=overlaod)
Thebalanceisswitchedoffbypressing fora longtime.
6.2 Taring
In weighing mode place a tare vessel on the weighing pan
and press
. The display goes to „0“, the weight of the
vessel is now saved internally. If the weight is heavier than
the zeroing range“ (20d), „NET“ is displayed.
Place the weighing good and read the measured value.
The bargraph appears according to the placed weight.
(example)
If you press again the button after finishing the weighing process, „0“ will
appear again.
The taring process can be repeated any number of times, e.g. when adding several
components for a mixture (adding).
The limit is reached when the whole weighing range is allocated.
After removing the taring container the total weight is displayed as negative display.

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6.3 Weighing Units
The balance can display different units.
Switch-over takes place in the menu under menu item „unit“.
Display
indication
Conversion factor
1 g =
Gram *
g
1.
Ounce
oz
0.035273962
Troy ounce
ozt
0.032150747
Pennyweight
dwt
0.643014931
Grain
gn
15.4324
Pound
lb
0.00220462
7 Menu
7.1 Navigation in the menu
Access to menu
In weighing mode press button
long time, „unit“ is
displayed.
Select menu items
With help of
, the individual menu items can be
selected one after the other.
Change settings
Confirm the selected menu item by , the current
setting is displayed.
Select desired setting with and acknowledge by
.

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7.2 Menu overview
unit Weighing Units: dwt, g, gn, oz, ozt, lb
cALE Adjustment with specified adjustment weight
tr Auto-Zero Tracking
AF Auto off selectable after 30, 60, 180 sec., off
rESEt Back to factory setting
EXit Return to weighing mode
7.3 Description of individual menu items
7.3.1 Weighing units switch-over
Condition: Menu item „unit“
Confirm „unit“ by , the weighing unit set as last is displayed.
Switch-over the weighing units by until the desired unit appears. Confirm
these units by , the unit flashes shortly before the balance returns to the
menu.
Press to go till to the menu item „Exit“ and confirm by . The balance
changes into weighing mode, the new weighing unit is now adjusted.
7.3.2 Zero tracking
The Auto-Zero function is used to tare small variations in weight automatically.
In the event that small quantities are removed or added to the material to be weighed,
incorrect weighing results can be displayed due to the “stability compensation“.
(Example: Slowly draining fluids from a container on the balance).
When apportioning involves small variations of weight, it is advisable to switch off this
function.
If Zero-Tracking however is switched off, the weighing display becomes more busy.

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Enable/disable zero tracking:
Condition: Menu item „tr“:
Confirm menu item by
Press to select between the following settings:
Display
Adjustment
„on“ Auto-Zero switched on
„oFF“ Auto-Zero switched off
Acknowledge desired selection by . Press to go till to the menu item
„Exit“ and confirm by . The balance changes into weighing mode.
7.3.3 AUTO-OFF function
For battery mode, the balance has an automatic switch-off function which in the menu
can be enabled or disabled. Proceed as follows:
Condition: Menu item „AF“:
Confirm by pressing
Press to select between the following settings:
Display Adjustment
AF oFF Continous operation
AF 30, 60, 180 To save the battery, the balance switches off automatically
after 30 or 60, or 180 seconds after the finished weighing
process
Acknowledge selection by . The display flashes shortly and then returns to the
menu. Press to go till to the menu item „Exit“ and confirm by . The
balance changes into weighing mode.

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7.3.4 Reset function
Menu reset to factory settings.
Condition: Menu item „rESEt“:
Acknowledge with . In the display the current setting appears.
Press to select between the following settings:
Display
Adjustment
YES Menu reset to factory settings.
no No menu reset to factory settings.
Acknowledge selection by . The display returns to the menu. Press to
go till to the menu item „Exit“ and confirm by . The balance changes into
weighing mode.
8 Servicing, maintenance, disposal
8.1 Cleaning
Before cleaning, please disconnect the appliance from the operating voltage.
Please do not use aggressive cleaning agents (solvents or similar agents), but a
cloth dampened with mild soap suds. Ensure that no liquid penetrates into the device
and wipe with a dry soft cloth.
Loose residue sample/powder can be removed carefully with a brush or manual
vacuum cleaner.
Spilled weighing goods must be removed immediately.
8.2 Servicing, maintenance
The appliance may only be opened by trained service technicians who are authorized
by KERN. Before opening, disconnect from power supply.
8.3 Disposal
Disposalof packaging and appliance must becarried outby operatoraccordingto valid
national or regional law of the location where the appliance is used.

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9 Instant help for troubleshooting
In case of an error in the program process, briefly turn off the balance and disconnect
from power supply. The weighing process must then be restarted from the beginning.
Help:
Fault Possible cause
The displayed weight does not glow. •The balance is not switched on.
•Batteries are inserted incorrectly or
empty
•No batteries inserted.
•The mains supply connection has
been interrupted (mains cable not
plugged in/faulty).
•Power supply interrupted.
The displayed weight is permanently •Draught/air movement
changing •Table/floor vibrations
•Weighing pan has contact with other
objects.
•
Electromagnetic fields / static charging
(choose different location/switch off
interfering device if possible)
The weighing value is obviously
wrong
•The display of the balance is not at
zero
•Adjustment is no longer correct.
•Great fluctuations in temperature.
•
Electromagnetic fields / static charging
(choose different location/switch off
interfering device if possible)
Should other error messages occur, switch balance off and then on again. If the error
message remains inform manufacturer.

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10 Declaration of conformity
The current EC/EU Conformity declaration can be found online in:
www.kern-sohn.com/ce