KERN & Sohn GmbH
Ziegelei 1
D-72336 Balingen
E-Mail: info@kern-sohn.com
Tel: +49-[0]7433- 9933-0
Fax: +49-[0]7433-9933-149
Internet: www.kern-sohn.com
Operating instructions
Compact balance
KERN WTB-N
Version 2.0
09/2012
GB
WTB-N-BA-e-1220
WTB-N-BA-e-1220 2
GB
KERN WTB-N
Version 2.0 09/2012
Operating instructions
Compact balance
Contents
1 Technical data ............................................................................................ 3
1.1 Dimensions............................................................................................................................. 5
2 Appliance overview .................................................................................... 6
2.1 Overview of display ................................................................................................................ 6
2.2 Keyboard overview ................................................................................................................. 8
3 Basic Information (General) ...................................................................... 9
3.1 Proper use .............................................................................................................................. 9
3.2 Improper Use ......................................................................................................................... 9
3.3 Warranty ................................................................................................................................. 9
3.4 Monitoring of Test Resources ................................................................................................ 9
4 Basic Safety Precautions ........................................................................ 10
4.1 Pay attention to the instructions in the Operation Manual ................................................... 10
4.2 Personnel training ................................................................................................................ 10
5 Transport and storage ............................................................................. 10
5.1 Testing upon acceptance ..................................................................................................... 10
5.2 Packaging / return transport ................................................................................................. 10
6 Unpacking, Setup and Commissioning .................................................. 11
6.1 Installation Site, Location of Use .......................................................................................... 11
6.2 Unpacking and placing ......................................................................................................... 12
6.2.1 Scope of delivery .................................................................................................................. 14
6.3 Rechargeable battery operation (optional) ........................................................................... 14
6.3.1 Mains connection during rechargeable battery operation .................................................... 16
6.4 Initial Commissioning ........................................................................................................... 17
6.5 Type of protection IP65 ........................................................................................................ 17
7 Adjustment ............................................................................................... 17
7.1 Adjustment ........................................................................................................................... 17
7.1.1 Adjustment ........................................................................................................................... 18
8 Operation .................................................................................................. 19
8.1 Weighing .............................................................................................................................. 19
8.2 Taring ................................................................................................................................... 19
8.3 Background illumination ....................................................................................................... 20
8.4 Weighing with tolerance range ............................................................................................. 21
9 The menu .................................................................................................. 23
9.1 Navigation in the menu ........................................................................................................ 23
9.2 Menu overview ..................................................................................................................... 24
9.3 Set auto-OFF function .......................................................................................................... 25
9.4 Multi-Tare function ............................................................................................................... 26
10 Error messages ........................................................................................ 26
11 Instant help ............................................................................................... 27
12 Service, maintenance, disposal .............................................................. 28
12.1 Cleaning ............................................................................................................................... 28
12.2 Service, maintenance ........................................................................................................... 28
12.3 Disposal................................................................................................................................ 28
3 WTB-N-BA-e-1220
1 Technical data
KERN
WTB
1K -4N
WTB
3K -3N
WTB
6K -3N
Weighing range (max)
1.5 kg
3 kg
6 kg
Readability (d)
0.2 g
0.5 g
1 g
Reproducibility
0.2 g
0.5 g
1 g
Linearity
±0.4 g
±1 g
±2 g
Recommended adjustment
weight, not added (class)
1500 g
(M1)
3 kg
(M1)
6 kg
(M1)
Stabilization time (typical)
2 sec.
Units
kg
Warm-up time
30 min.
Electric Supply
Input voltage: 110V-230V AC
Power supply unit: 12 V, 500 mA
Rechargeable battery
operation
Service life: background illumination ON: 30 h
Background illumination off: 50 hours
Loading time 12 h
Auto-Off (rechargeable
battery)
15 min., 5 min., 3 min., off
Display type
LCD with background illumination
Character height 2.5 cm
Operating temperature
-10° C …. + 40° C
Humidity of air
0 % - 80 % (non-condensing)
Dimensions of weighing plate
(Stainless steel) (mm)
262 x 202
Casing dimensions
286 x 316 x 126.5
Weight kg (net)
3.2
IP protection
IP65
WTB-N-BA-e-1220 4
KERN
WTB
10K -3N
WTB
30K -3N
Weighing range (max)
15 kg
30 kg
Readability (d)
2 g
5 g
Reproducibility
2 g
5 g
Linearity
±4 g
±10 g
Recommended adjustment
weight, not added (class)
15 kg
(M1)
30 kg
(M1)
Stabilization time (typical)
2 sec.
Units
kg
Warm-up time
30 min.
Electric Supply
Input voltage: 110V-230V AC
Power supply unit: 12 V, 500 mA
Rechargeable battery
operation
Service life: background illumination ON: 30 h
Background illumination off: 50 hours
Loading time: 12 h
Auto-Off (rechargeable
battery)
15 min., 5 min., 3 min., off
Display type
LCD, digit height 25 mm
Operating temperature
-10° C …. + 40° C
Humidity of air
0 % - 80 % (non-condensing)
Dimensions of weighing plate
(Stainless steel) (mm)
262 x 202
Casing dimensions
286 x 316 x 126.5
Weight kg (net)
3.2
IP protection
IP65
5 WTB-N-BA-e-1220
1.1 Dimensions
WTB-N-BA-e-1220 6
2 Appliance overview
1 Weighing plate
2 Keyboard
3 Bubble level
4 Display
2.1 Overview of display
Rear view:
7 WTB-N-BA-e-1220
Display
Description
Description
Zeroing display
Should the balance not display exactly zero
despite empty scale pan, press the
button. The balance will be set to zero after a
short standby time.
Stability display
Scales are in a steady state
Net weight display
Net weight will be displayed
Capacity display
Rechargeable battery
Triangle above the capacity indicator appears
when the battery capacity is almost exhausted
Display Weighing with
tolerance range
Triangle above "+": upper limit value
Triangle above "-": lower limit value
Power supply connected
Lights with power supply via power supply unit,
then the battery is being charged
Display Weighing unit kg
Displayed weight in kg
WTB-N-BA-e-1220 8
2.2 Keyboard overview
Key
Description
Function
in menu
ON/OFF-switch
Turn on/off
TARE button
Tare balance
Weighing with
tolerance range
Call up menu
Change to the next menu
item /parameter
Zero setting key
Set balance to zero
Select menu item /
parameter
+
Push TARE + reset
button
simultaneously
Switch-over units
9 WTB-N-BA-e-1220
3 Basic Information (General)
3.1 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 balcance”, 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.
3.2 Improper Use
Do not use balance for dynamic weighings. 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.
3.3 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 or damage by media, liquids, natural wear and tear
The appliance is improperly set up or incorrectly electrically connected
The measuring system is overloaded
3.4 Monitoring of Test Resources
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 substances 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.
WTB-N-BA-e-1220 10
4 Basic Safety Precautions
4.1 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.
All language versions contain a non-binding translation. The original
German is binding.
4.2 Personnel training
The appliance may only be operated and maintained by trained personnel.
5 Transport and storage
5.1 Testing upon acceptance
When receiving the appliance, please check packaging immediately, and the
appliance itself when unpacking for possible visible damage.
5.2 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 remove 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.
11 WTB-N-BA-e-1220
6 Unpacking, Setup and Commissioning
6.1 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 scales on a stable, even 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 charge of goods to be weighed or weighing container.
Major display deviations (incorrect weighing results) may be experienced should
electromagnetic fields (e.g. due to mobile phones or radio equipment), static
electricity accumulations or instable power supply occur. Change location or remove
source of interference.
WTB-N-BA-e-1220 12
6.2 Unpacking and placing
Carefully remove the balance from the packaging, remove plastic cover and setup
balance at the intended workstation.
1
Weighing pan
2
Locking screw
3
Carrier weighing plate
4
Shim
5
Display
6
Bubble level
7
Keyboard
8
Footscrews
9
Rechargeable battery compartment cover
10
Screws of battery compartment cover
13 WTB-N-BA-e-1220
Level balance with foot screws until the air bubble of the water balance is in the
prescribed circle.
1 Rechargeable battery
compartment
2 Mains port
3 Pressure compensation screw
Pressure compensation screw:
[1]
On the lower side of the balance there is a pressure compensation screw [1] which
has to be opened for the weighing process. Fasten the screw before cleaning the
balance.
WTB-N-BA-e-1220 14
6.2.1 Scope of delivery
Serial accessories:
Balance
Weighing pan
Carrier weighing plate
Fastening screw of the carrier weighing plate
Operating instructions
Hexagonal socket wrench
6.3 Rechargeable battery operation (optional)
The rechargeable battery is charged via the delivered power supply.
The operating time of the rechargeable battery with background illumination is 30h,
without that it is 50 hrs. Charging time until complete recharging 12h.
In the menu you can activate the AUTO-OFF function time off], see chap. 9.2.
According to menu settings, the balance switches automatically off in order to spare
the battery.
Insert rechargeable battery:
Remove any
adherent moisture
from the balance
Rotate both levers
(1) 90 degrees to the
left
Membrane for degree of
protection IP65
15 WTB-N-BA-e-1220
Remove battery compartment
cover and the foam pieces
Connecting the rechargeable
battery
Watch the colours:
Red on red !
Black on black!
Insert the rechargeable battery
in a manner that it cannot slip
(fasten with a rubber foam mat)
Ensure that the cables are
not squeezed.
WTB-N-BA-e-1220 16
Close the rechargeable battery
cover
Rotate both levers (1) 90 degrees to
the right
If in the display the triangle appears above the capacity display , the
rechargeable battery is nearly exhausted. Connect power pack, the rechargeable
battery is loaded.
Avoid excess pressure on the balance in order to avoid damaging
it, particularly as it is supported by the weighing plate.
6.3.1 Mains connection during rechargeable battery operation
During the rechargeable battery operation ensure that the mains
connection is covered with a rubber cap.
Only by this the type of protection IP65 is ensured.
17 WTB-N-BA-e-1220
6.4 Initial Commissioning
In order to obtain exact results with the electronic balances, your balance must have
reached the operating temperature (see warming up time chap. 1).
For this warm-up period the scale must be connected to the power supply (batteries).
The accuracy of the balance depends on the local acceleration of gravity.
Strictly observe hints in chapter Adjustment.
6.5 Type of protection IP65
The KERN WTB meets the requirements for IP65 protection type.
Suitable for a short-time contact with liquids. For cleaning use damp cloth. Dust-tight.
7 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.
7.1 Adjustment
Carry out adjustment as close as possible to the maximum load of the scales )see
chap. 1 „Technical data“). The accuracy of the adjustment weight must correspond
approximately to or, if possible, be better than, the readability d of the balance.
Information about test weights you will find in the internet under http://www.kern-
sohn.com
Procedure when adjusting:
Observe stable environmental conditions. A warming up time (see chapter 1) is
required for stabilization.
WTB-N-BA-e-1220 18
7.1.1 Adjustment
Display
Operation
Start balance by pressing
While the balance carries out a self test (00…- 99…), press
and keep pressed until „F1 CAL“ appears on the
display.
Press ;
in the display appears „UnLod“. Wait for the triangle above
the stability symbol, then press , the value of the last-
used adjustment weight is displayed. Exp: „6 kg“. If
necessary, change value by .
(example)
Place the adjustment weight
Wait for the triangle above the stability symbol
Press
While the balance carries out a self-test, take away the
adjustment weight
The balance changes over to zero display.
Now the process of adjustment is completed.
If the display shows an error message or an incorrect value, repeat adjustment
process. If the error message remains, please contact your dealer.
19 WTB-N-BA-e-1220
8 Operation
8.1 Weighing
Start balance by pressing .
The balance will carry out a self-test
When the weight display shows "0.0" and the triangle symbol
above the stability display appears, the scale is ready
for weighing.
However, you can reset the weighing scale to zero by pressing
the key.
Switch off balance using .
The "0.0" display disappears and the scales are switched off.
8.2 Taring
The tare weight of any preloads can be deducted by pressing a button so that the
actual weight of the weighed material is displayed in subsequent weighings.
(example)
Put on weighing receptacles and press .
The zero display appears, and above the reset symbol
the stability symbol and the net weight symbol the
triangle appears.
The weight of the container is now internally saved.
(example)
Place goods to be weighed in the weighing container.
The net weight of the goods to be weighed is displayed.
The weight of the weighing container will be displayed as a
minus number (=gross weight) after removing the weighing
container.
WTB-N-BA-e-1220 20
The tare weight is saved until it is deleted. Remove the load
from the balance and press . The zero display appears
and the triangle above the net weight symbol
vanishes.
Gross weight:
Press as long as the weighing container and the
object to be weighed are on the weighing plate.
Remove the object to be weighed as well as the weighing
container.
The gross weight is displayed as a negative value.
8.3 Background illumination
In weighing mode press for about 3 seconds, "bK-AU"
appears.
Press to select background illumination automatically
off („bK-AU“) and background illumination off („bK-oF“).
Press to confirm selected setting.
The balance changes into weighing mode
21 WTB-N-BA-e-1220
8.4 Weighing with tolerance range
You can set an upper or lower limit when weighing with tolerance range and thus
ensure that the weighed load remains exactly within the set tolerance limits.
Settings:
(example)
(example)
In weighing mode press for about 3 seconds, the
display for entering the upper limit appears. The left digit
blinks. A triangle appears above the "+" symbol.
Moreover, the background of the screen turns red.
Enter upper limit value, the active position blinks.
Mit Correct the numerical value by , change the
decimal using . If the last digit is entered, confirm input
by , the upper limit value is hereby saved.
The display changes to the prompt for entering the lower limit
value.
The colour of the display then changes to orange.
Now enter the lower limit value as described above and
confirm input using . The lower limit value is thus
entered. The balance changes into weighing mode.
Audio signal:
The acoustic signal depends on the settings in menu block „F9 BEP“.
Options:
BEP 0
Acoustic signal turned off
BEP 1
An acoustic signal sounds when load is within tolerance limits
BEP 2
An acoustic signal sounds when load is beyond tolerance limits
WTB-N-BA-e-1220 22
Optical signals:
The triangle above the "+" - or the "-" symbol indicates whether the sample weighed
is within the tolerance range:
Goods to be weighed above tolerance limit
Goods to be weighed within tolerance range
Goods to be weighed below tolerance limit
Traffic light function:
The indicator lights up in red, green and orange, depending on the area in which your
sample is:
red
Goods to be weighed above tolerance limit
green
Goods to be weighed within tolerance range
orange
Goods to be weighed below tolerance limit
Weighing with tolerance range
Tare when using a weighing container
Put on goods to be weighed, tolerance control is started
Load below specified
tolerance
Load within specified
tolerance
Load exceeds specified
tolerance
orange background
green background
red background
23 WTB-N-BA-e-1220
9 The menu
9.1 Navigation in the menu
Switch on the scales by and during the balance’s self-
test, press until "F1 CAL" is displayed.
Use to change to the next menu item
Select menu item using
Use to change between the individual parameters
Select the desired parameter using
WTB-N-BA-e-1220 24
9.2 Menu overview
Menu item
Function
Adjustment process.
3000
6000
dual
Resolution
Please do not change default
setting
1.5 kg
3 kg
6 kg
15 kg
25 kg
30 kg
Max load
Do not change the default
setting
not documented
3 min
5 min
15 min
off
Auto-OFF function,
adjustable between off, 3, 5
and 15 minutes
not documented
SP 7.5
SP 15
SP 30
SP 60
Display speed
Do not change the default
setting
Multi-Tare function:
0 tare Multi-Tare function disabled
P tare Multi-Tare function enabled
Acoustic signal in tolerance weighing mode
bEP 0
Acoustic signal turned off
bEP 1
Acoustic signal when weighed material is
within the tolerance range
bEP 2
Acoustic signal when weighed material is
outside the tolerance range
Return to weighing mode
25 WTB-N-BA-e-1220
9.3 Set auto-OFF function
Switch on the scales by and during the balance’s self-
test, press until "F1 CAL" is displayed.
Press repeatedly until „F5 oFF“ appears
Select function using
Use to change between the individual parameters
Select the desired parameter using
“F5 oFF“ appears, now the function is enabled
Press repeatedly until “bACK“ appears
Press
The balance carries out a restart and changes to weighing
mode
WTB-N-BA-e-1220 26
9.4 Multi-Tare function
The scale has the ability to tare several times in a row. For this purpose, select the
menu item "F8 tm" and set the parameter "P tare".
10 Error messages
Display
Description
Remedy
Zero range exceeded
Unload the balance
A/D converter outside range
Unload the balance; check if
the weighing is correctly
placed and screwed on
27 WTB-N-BA-e-1220
11 Instant help
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.
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 displayed weight is permanently
changing
Draught/air movement
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.
The balance is on an uneven surface.
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.
WTB-N-BA-e-1220 28
12 Service, maintenance, disposal
12.1 Cleaning
Before cleaning, please remove batteries from the appliance
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.
12.2 Service, maintenance
The appliance may only be opened by trained service technicians who are authorized
by KERN.
Before opening, disconnect from power supply.
12.3 Disposal
Disposal of packaging and appliance must be carried out by operator according to
valid national or regional law of the location where the appliance is used.
29 WTB-N-BA-e-1220
Note on battery recycling regulations ( BattV)
Applies to Germany only!
In our capacity as retailers we are obliged in connection with the distribution of
batteries and storage batteries to inform our end users as follows:
End users are bound by law to return waste batteries / storage batteries. Batteries /
storage batteries can be returned to municipal collection points or specialist shops
whilst taking into account common expiration times.
Precautions against short circuit must be taken in cases where the service life has
not yet expired.
Batteries containing noxious substances bear a symbol consisting of a crossed-
out bin plus the chemical symbol (Cd = cadmium, Hg = quicksilver, or Pb =
lead) of the heavy metal crucial for the classification of the noxious substance.
Batteries with a low degree of noxious substances bear merely a crossed out
bin.
Return options are restricted to the types of battery that we keep or used to keep in
stock as well as the quantity commonly disposed of by end users.
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