KERN PRS, PRJ, ARS, ARJ Operating Instruction

PRS/PRJ/ARS/ARJ-BA-def-0622 85

KERN & Sohn GmbH

Ziegelei 1
D-72336 Balingen
E-Mail: [e-mail]

Tel: +49-[0]7433- 9933-0
Fax: +49-[0]7433-9933-149
Internet: www.kern-sohn.com

Operating instruction
Precision and analytical balances

KERN PRS/PRJ/ARS/ARJ

Version 2.2
11/2006
GB

PRS/PRJ/ARS/ARJ-BA-e-0622

86 PRS/PRJ/ARS/ARJ-BA-def-0622

GB

KERN PRS/PRJ/ARS/ARJ

Version 2.2 11/2006

Operating Instructions
Precision and analytical balance

Table of Contents

1 Technical data _____________________________________________________89
2 Declaration of conformity____________________________________________95
3 Fundamental information (general)____________________________________ 97

3.1 Intended use ________________________________________________________97

3.2 Inappropriate use ____________________________________________________97

3.3 Guarantee __________________________________________________________97

3.4 Monitoring the test equipment__________________________________________98

4 Fundamental safety information ______________________________________98

4.1 Observe the information in the operating instructions______________________98

4.2 Staff training ________________________________________________________98

5 Transport and storage ______________________________________________98

5.1 Acceptance check____________________________________________________98

5.2 Packaging __________________________________________________________98

6 Unpacking, installation and commissioning ____________________________99

6.1 Place of installation, place of use _______________________________________99

6.2 Unpacking __________________________________________________________99

6.3 Installation _________________________________________________________100

6.3.1 Windshield for PRS and PRJ balances (d=0.1 mg)_______________________________ 101

6.4 Functions of the balance _____________________________________________102

6.5 Equipment overview: ________________________________________________103

6.6 Scope of delivery ___________________________________________________104

6.7 Mains supply _______________________________________________________105

6.8 Connecting peripheral devices ________________________________________105

6.9 Commissioning _____________________________________________________105

6.10 Calibration _________________________________________________________105

6.10.1 External calibration by means of ICM _______________________________________ 106

6.10.2 External calibration with freely selectable weight ______________________________ 107

6.10.3 Internal calibration (only ARJ/PRJ models) __________________________________ 108

6.10.4 Automatic calibration (only ARJ/PRJ models)_________________________________ 108

6.10.5 Balances appropriate for verification (only ARJ/PRJ models)_____________________ 109

6.10.6 Position of verification safety seal (only on ARJ/P RJ models appropriate for verification)110

6.11 Suspended weighing ________________________________________________111

7 Modes of operation and use_________________________________________112

PRS/PRJ/ARS/ARJ-BA-def-0622 87

7.1 Switching on the balance_____________________________________________112

7.2 Auto-Standby-Mode _________________________________________________112

7.3 Significance of the two main menus____________________________________112

7.4 Activating the two main menus ________________________________________113

7.4.1 Activating the configuration menu ____________________________________________ 113

7.4.2 Activating the application menu______________________________________________ 113

7.5 How the menu control operates________________________________________113

7.5.1 Control panel____________________________________________________________ 114

7.5.2 Operation in weighing mode ________________________________________________ 114

7.5.3 Operation in programming mode_____________________________________________ 115

7.5.4 Display_________________________________________________________________ 116

7.5.5 Info-line and function keys__________________________________________________ 116

7.5.6 Example of display: Statistics program ________________________________________ 117

7.6 Password protection of the menus _____________________________________118

7.7 Anti-theft encoding __________________________________________________118

8 Working with the configuration menu_________________________________120

8.1 Structure of the configuration menu____________________________________120

8.2 Language function __________________________________________________121

8.3 Defining the configuration ____________________________________________122

8.4 Selecting the weight unit _____________________________________________122

8.5 Print functions______________________________________________________123

8.6 Calibration functions ________________________________________________124

8.7 Weighing mode _____________________________________________________125

8.8 Interface functions __________________________________________________126

8.9 Date and time (only PRJ and ARJ models) ________________________________126

8.10 Password protection_________________________________________________127

8.11 Anti-theft encoding __________________________________________________127

9 Working with the application menu___________________________________128

9.1 Structure of the application menu______________________________________128

9.2 Selecting an application______________________________________________129

9.3 Setup for “SET APP UNITS”: __________________________________________130

9.4 Setup for “SET APP COUNT”__________________________________________131

9.5 Setup for “SET APP PERCENT” _______________________________________132

9.6 Setup for “SET APP CALCULATOR”____________________________________133

9.7 Setup for “SET APP PAPER”__________________________________________134

9.8 Setup for “SET APP NET TOTAL” ______________________________________135

9.9 Setup for “SET APP TOTALISE” _______________________________________136

9.10 Setup for “SET APP ANIMAL WEIGHING” _______________________________137

9.11 Setup for “SET APP DENSITY” ________________________________________138

9.12 Setup for the statistics program _______________________________________140

9.13 Setup for CHECK weighing ___________________________________________142

88 PRS/PRJ/ARS/ARJ-BA-def-0622

10 Special operating keys ___________________________________________143

10.1 The Tare key “T” ____________________________________________________143

10.2 The CAL key “CAL”__________________________________________________143

10.3 The Print key “PRINT” _______________________________________________144

10.4 The Change key « » _______________________________________________144

11 Data transfer to peripheral devices _________________________________145

11.1 Connection to peripheral devices ______________________________________146

11.2 Data transfer _______________________________________________________147

11.3 Remote-control commands ___________________________________________148

11.4 Examples for the remote control of the balance __________________________149

12 Practical examples ______________________________________________150

12.1 Changing the configuration menu______________________________________150

12.1.1 Setting the choice of language ____________________________________________ 150

12.1.2 Setting the Weight unit __________________________________________________ 150

12.1.3 Setting the Print functions________________________________________________ 151

12.1.4 Activation of password protection __________________________________________ 152

12.2 Selecting an application program ______________________________________153

12.2.1 Setting for Counting by weighing___________________________________________ 153

12.2.2 Setting the statistics function______________________________________________ 155

13 Further information ______________________________________________158

13.1 Notes on Weighing mode_____________________________________________158

13.1.1 Set Weighing mode: Floati ng display _______________________________________ 158

13.1.2 Set Weighing mode: Stability control________________________________________ 158

13.1.3 Set Weighing mode: Auto-Standby_________________________________________ 159

13.1.4 Set Weighing mode: Auto-Zero____________________________________________ 159

13.2 Notes on density determination________________________________________160

13.2.1 Density determination “Solid on bottom mode ”________________________________ 160

13.2.2 Density determination “Solid in air mode”____________________________________ 160

13.2.3 Density determination “Liquid mode”________________________________________ 160

13.2.4 14.3.4 Density determination “Porous solid mode” _____________________________ 160

14 Configuration menu tree__________________________________________161
15 Application Menu Tree ___________________________________________ 164

15.1 Software updates via Internet _________________________________________165

16 Servicing, maintenance, disposal __________________________________165

16.1 Cleaning___________________________________________________________165

16.2 Servicing, maintenance ______________________________________________165

16.3 Disposal ___________________________________________________________165

17 Troubleshooting ________________________________________________166
18 Error messages and correction of faults_____________________________167

18.1 Notes on correcting faults ____________________________________________167

PRS/PRJ/ARS/ARJ-BA-def-0622 89

1 Technical data

KERN PRS 320-3N PRS 620-3N PRS 4200-2N PRS 4200-

2IP65N

Readout (d) 0.001 g 0.001 g 0.01 g 0.01 g
Weighing range (Max) 320 g 620 g 4,200 g 4,200 g
Repeatability 1 mg 1 mg 10 mg 10 mg
Linearity ± 1.5 mg ± 1.5 mg ± 15 mg ± 15 mg
Recommended adjusting

weight, not included (class)

200 g (E2) 500 g (E2) 4000 g (E2) 4000 g (E2)

Minimum piece weight in
count mode

0.001 g 0.001 g 0.01 g 0.01 g

Reference quantity when
counting parts

1-999 1-999 1-999 1-999

Weighing plate, stainless
steel [mm]

135 x 135 135 x 135 170 x 170 170 x 170

Dimensions of housing
(W x D x H) [mm]

210 x 340 x 150 210 x 340 x 150 210 x 340 x 150 210 x 340 x 150

Dimensions of weighing
space glass windshield
[mm]

155 x 155 x 55 155 x 155 x 55 - -

Net weight (kg) 5.1 5.1 4.5 4.5
Stabilisation time 2 seconds
Weight units

(verified equipment)

mg, g

Weight units
(non-verified equipment)

mg, g, GN, dwt, ozt, oz, lb, ct, C.M. tLH, tLM, tLT, mo, Tola

Permissible ambient
conditions

10° C to 30° C

Air humidity max. 80 % relative (non condensing)

90 PRS/PRJ/ARS/ARJ-BA-def-0622

KERN PRS 6200-2N PRS 8200-1N PRS 8200-1IP65N PRS 12200-1N

Readout (d) 0.01 g 0.1 g 0.1 g 0.1 g
Weighing range (Max) 6,200 g 8,200 g 8,200 g 12,200 g
Repeatability 10 mg 0.1 g 0.1 g 0.1 g
Linearity ± 15 mg ± 0.1 g ± 0.1 g ± 0.1 g
Recommended adjusting

weight, not included (class)

5000 g (E2) 5000 g (F2) 5000 g (F2) 10 000 g (F1)

Minimum piece weight in
count mode

0.01 g 0.1 g 0.1 g 0.1 g

Reference quantity when
counting parts

1-999 1-999 1-999 1-999

Weighing plate, stainless
steel [mm]

170 x 170 200 x 200 200 x 200 200 x 200

Dimensions of housing
(W x D x H) [mm]

210 x 340 x 150 210 x 340 x 150 210 x 340 x 150

210 x 340 x

150

Net weight (kg) 4.5 4.7 4.7 4.7
Stabilisation time 2 seconds
Weight units

(verified equipment)

mg, g

Weight units
(non-verified equipment)

mg, g, GN, dwt, ozt, oz, lb, ct, C.M. tLH, tLM, tLT, mo, Tola

Permissible ambient
conditions

10° C to 30° C

Air humidity max. 80 % relative (non condensing)

PRS/PRJ/ARS/ARJ-BA-def-0622 91

KERN PRS 12200-

1IP65N

PRJ 320-3NM PRJ 620-3NM PRJ 1200-3N

Readout (d) 0.1 g 0.001 g 0.001 g 0.001 g
Weighing range (Max) 12,200 g 320 g 620 g 1,220 g
Minimum load - 0.02 g 0.02 g ­Verification value - 0.01 g 0.01 g ­Verification categories - II II ­Repeatability 0.1 g 1 mg 1 mg 1 mg
Linearity ± 0.1 g ± 1.5 mg ± 1.5 mg ± 2 m g
Recommended adjustment

weight

10 000 g (F1) - - -

Adjustment weight - internal internal internal
Minimum piece weight in

count mode

0.1 g 0.001 g 0.001 g 0.001 g

Reference quantity when
counting parts

1-999 1-999 1-999 1-999

Weighing plate, stainless
steel [mm]

200 x 200 135 x 135 135 x 135 135 x 135

Dimensions of housing
(W x D x H) [mm]

210 x 340 x 150

210 x 340 x

150

210 x 340 x 150

210 x 340 x

150

Dimensions of glass
windshield [mm]

-

Weighing

space 155 x

155 x 55

Weighing space

155 x 155 x 55

150 x 150 x 60

Net weight (kg) 4.7 5.5 5.5 5.5
Weight units

mg, g, GN, dwt,

ozt, oz, lb, ct, C.M.

tLH, tLM, tLT, mo,

Tola

mg, g mg, g

mg, g, GN,

dwt, ozt, oz, lb,

ct, C.M. tLH,

tLM, tLT, mo,

Tola

Permissible ambient
conditions

10° C to 30° C

Stabilisation time 2 seconds
Air humidity max. 80 % relative (non condensing)

92 PRS/PRJ/ARS/ARJ-BA-def-0622

KERN PRJ 4200-2NM PRJ 6200-2NM PRJ 6200-1IP65NM PRJ 8200-1NM

Readout (d) 0.01 g 0.01 g 0.1 g 0.1 g
Weighing range (Max) 4,200 g 6,200 g 6,200 g 8,200 g
Minimum load 0.5 g 0.5 g 5 g 5 g
Verification value 0.1 g 0.1 g 1 g 1 g
Verification categories II II II II
Repeatability 10 mg 10 mg 0.1 g 0.1 g
Linearity ± 15 mg ± 15 mg ± 0.1 g ± 0.1 g
Adjustment weight internal internal internal internal
Minimum piece weight in

count mode

0.01 g 0.01 g 0.1 g 0.1 g

Reference quantity when
counting parts

1-999 1-999 1-999 1-999

Weighing plate, stainless
steel [mm]

170 x 170 170 x 170 200 x 200 200 x 200

Dimensions of housing
(W x D x H) [mm]

210 x 340 x

150

210 x 340 x

150

210 x 340 x 150

210 x 340 x

150

Net weight (kg) 5.5 5.5 5.6 5.6
Weight units

mg, g, kg

Permissible ambient
conditions

10° C to 30° C

Stabilisation time 2 seconds
Air humidity max. 80 % relative (non condensing)

PRS/PRJ/ARS/ARJ-BA-def-0622 93

KERN PRJ 8200-

1IP65NM

PRJ 10200-

1IP65NM

ARS 120-4N ARS 220-4N

Readout (d) 0.1 g 0.1 g 0.1 mg 0.1 mg
Weighing range (Max) 8,200 g 10,200 g 120 g 220 g
Minimum load 5 g 5 g - ­Verification value 1 g 1 g - ­Verification categories II II - ­Repeatability 0.1 g 0.1 g 0.1 mg 0.1 mg
Linearity ± 0.1 g ± 0.1 g ± 0.2 mg ± 0.2 mg
Recommended adjusting

weight, not included (class)

- ­100 g (E2) 200 g (E2)

Adjustment weight internal internal
Minimum piece weight in

count mode

0.1 g 0.1 g 0.1 mg 0.1 mg

Reference quantity when
counting parts

1-999 1-999 1-999 1-999

Weighing plate, stainless
steel [mm]

200 x 200 200 x 200

Ø 80 Ø 80

Dimensions of housing
(W x D x H) [mm]

210 x 340 x 150

210 x 340 x

150

210 x 340 x 345 210 x 340 x 345

Dimensions of glass
windshield [mm]

- -

205 x 205 x 260
weighing space:
180 x 200 x 240

205 x 205 x 260
weighing space:
180 x 200 x 240

Net weight (kg) 5.6 5.6 5.9 5.9
Weight units

mg, g, kg mg, g, kg

mg, g, GN, dwt, ozt, oz, lb, ct, C.M.

tLH, tLM, tLT, mo, Tola

Permissible ambient
conditions

10° C to 30° C 15° C to 25° C

Stabilisation time 2 seconds 3 seconds
Air humidity max. 80 % relative (non condensing)

94 PRS/PRJ/ARS/ARJ-BA-def-0622

KERN ARJ 120-4NM ARJ 205-5DM ARJ 220-4NM

Readout (d) 0.1 mg 0.01/0.1 m g 0.1 mg
Weighing range (Max) 120 g 90/205 g 220 g
Minimum load 0.01 g 0.01 g 0.01 g
Verification value 1 mg 1 mg 1 mg
Verification categories I I I
Repeatability 0.1 mg 0.03/0.1 mg 0.1 mg
Linearity ± 0.2 mg ± 0.06/0.2 mg ± 0.2 mg
Stabilisation time 3 secon d s 10/3 seconds 3 seconds
Adjustment weight internal internal internal
Minimum piece weight in

count mode

0.1 mg 0.01 mg 0.1 mg

Reference quantity when
counting parts

1-999 1-999 1-999

Weighing plate, stainless
steel [mm]

Ø 80 Ø 80 Ø 80

Dimensions of housing
(W x D x H) [mm]

210 x 340 x 345 210 x 340 x 345 210 x 340 x 345

Dimensions of glass
windshield [mm]

205 x 205 x 260
weighing space:
180 x 200 x 240

205 x 205 x 260

205 x 205 x 260
weighing space:
180 x 200 x 240

Net weight (kg) 6.9 6.9 6.9
Weight units mg, g
Permissible ambient

conditions

15° C to 25° C

Air humidity max. 80 % relative (non condensing)

PRS/PRJ/ARS/ARJ-BA-def-0622 95

2 Declaration of conformity

KERN & Sohn GmbH

D-72322 Balingen-Frommern
Postfach 4052
E-Mail: [e-mail]

Tel: 0049-[0]7433- 9933-0
Fax: 0049-[0]7433-9933-149
Internet: www.kern-sohn.de

Declaration of conformity

Declaration of conformity for apparatus with CE mark

Konformitätserklärung für Geräte mit CE-Zeichen

Déclaration de conformité pour appareils portant la marque CE

Declaración de conformidad para aparatos con marca CE

Dichiarazione di conformitá per apparecchi contrassegnati con la marcatura CE

English

We hereby declare that the product to which this declaration refers conforms with the
following standards.

Deutsch

Wir erklären hiermit, dass das Produkt, auf das sich diese Erklärung bezieht, mit den
nachstehenden Normen übereinstimmt.

Français

Nous déclarons avec cela responsabilité que le produit, auquel se rapporte la présente
déclaration, est conforme aux normes citées ci-après.

Español

Manifestamos en la presente que el producto al que se refiere esta declaración está de
acuerdo con las normas siguientes.

Italiano

Dichiariamo con ciò che il prodotto al quale la presente dichiarazione si riferisce è
conforme alle norme di seguito citate.

Electronic Balance: KERN ARS, ARJ
KERN PRS, PRJ

Mark applied EU Directive Standards

89/336EEC EMC EN 50081-1

EN 50082-1
EN 55022

Date: 15.01.2006 Signature:

Gottl. KERN & Sohn GmbH
Management

Gottl. KERN & Sohn GmbH, Ziegelei 1, D-72336 Balingen, Tel. +49-[0]7433/9933-0,Fax +49-[0]7433/993 3-149

96 PRS/PRJ/ARS/ARJ-BA-def-0622

KERN & Sohn GmbH

D-72322 Balingen-Frommern
Postfach 4052
E-Mail: [e-mail]

Tel: 0049-[0]7433- 9933-0
Fax: 0049-[0]7433-9933-149
Internet: www.kern-sohn.de

Declaration of conformity

Declaration of conformity for apparatus with CE mark

Konformitätserklärung für Geräte mit CE-Zeichen

Déclaration de conformité pour appareils portant la marque CE

Declaración de conformidad para aparatos con marca CE

Dichiarazione di conformitá per apparecchi contrassegnati con la marcatura CE

English

We hereby declare that the product to which this declaration refers conforms with the following
standards. This declaration is only valid with the certificate of conformity by a notified body.

Deutsch

Wir erklären hiermit, dass das Produkt, auf das sich diese Erklärung bezieht, mit den
nachstehenden Normen übereinstimmt. Diese Erklärung gilt nur in Verbindung mit der

Konformitätsbescheinigung einer benannten Stelle.

Français

Nous déclarons avec cela responsabilité que le produit, auquel se rapporte la présente déclaration,
est conforme aux normes citées ci-après. Cette déclaration est valide seulement avec un

certificat de conformité d’un organisme notifié.

Español

Manifestamos en la presente que el producto al que se refiere esta declaración está de acuerdo
con las normas siguientes. Esta declaratión solo será válida acompañada del certificado de

conformidad de conformidad de la parte nominal.

Italiano

Dichiariamo con ciò che il prodotto al quale la presente dichiarazione si riferisce è conforme alle
norme di seguito citate. Questa dichiarazione sarà valida solo se accompagnata dal certificato

di conformità della parte nominale.

Model: KERN ARJ

PRJ 320-3NM
PRJ 620-3NM
PRJ 1200-3N
PRJ 4200-2NM
PRJ 6200-2NM

PRJ 6200-1IP65NM
PRJ 8200-1NM
PRJ 8200-1IP65NM
PRJ 10200-1IP65NM

EU Directive Standards

EC-type-approval
certificate no.

Issued by

90/384/EEC EN 45501 D00-09-029

PTB

Date: 15.01.2006 Signature:

Gottl. KERN & Sohn GmbH
Management

Gottl. KERN & Sohn GmbH, Ziegelei 1, D-72336 Balingen, Tel. [phone],Fax [phone]

PRS/PRJ/ARS/ARJ-BA-def-0622 97

3 Fundamental information (general)

3.1 Intended use

The balance you have purchased is to be used to determine the weight of the 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 plate. The
weighing value can be read off after a stable weighing value has been obtained.

3.2 Inappropriate use

Do not use the balance for dynamic weighing, if small quantities of the material to be
weighed are removed or added. The “stability compensation” function in the balance itself
can result in incorrect weighing results being displayed! (Example: Slowly draining fluids
from a container on the balance.)
Do not leave a permanent load on the weighing plate. This can damage the measuring
equipment.
Be sure to avoid impact shock and overloading the balance in excess of the prescribed
maximum load rating (max.), minus any possible tare weight that is already present. This
could cause damage to the balance.
Never operate the balance in hazardous areas. The standard model is not explosion­proof.
Structural alterations may not be made to the balance. This can lead to incorrect weighing
results, faults concerning safety regulations and also to serious damage to the balance.
The balance may only be used in compliance with the described guidelines. Varying
areas of application/planned use must be approved by KERN in writing.

3.3 Guarantee

The guarantee is not valid following

• non-observation of our guidelines in the operating instructions

• use other than for the applications described

• alteration to or opening of the device

• mechanical damage and damage caused by media, liquids, or natural wear and tear

• inappropriate installation or electric installation

• overloading of the measuring equipment

98 PRS/PRJ/ARS/ARJ-BA-def-0622

3.4 Monitoring the test equipment

The metrology features of the balance and any possible available test weight must be
checked at regular intervals within the scope of quality assurance. For this purpose, the
user responsible must define a suitable interval as well as the nature and scope of this
check. Please see KERN’s home page (www.kern-sohn.com) for information regarding
the monitoring of balance test equipment and the test weights required for this. Test
weights and balances can be calibrated quickly and at a reasonable price in KERN’s
accredited DKD calibration laboratory (return to national standard).

4 Fundamental safety information

4.1 Observe the information in the operating instructions

Please read the operating instructions carefully before installing and commissioning, even
if you already have experience with KERN balances.

4.2 Staff training

The device may only be operated and maintained by trained members of staff.

5 Transport and storage

5.1 Acceptance check

Please check the packaging immediately upon delivery and check the device during
unpacking for any visible signs of external damage.

5.2 Packaging

Please retain all parts of the original packaging in case it should be necessary to return
items at any time.
Only the original packaging should be used for return consignments.
Before despatch, disconnect all attached cables and loose/movable parts.
Affix any intended transport security devices. Secure all parts, e.g. weighing plate, power
supply unit etc. to prevent slipping and damage.

PRS/PRJ/ARS/ARJ-BA-def-0622 99

6 Unpacking, installation and commissioning

6.1 Place of installation, place of use

The balance is constructed in such a way that reliable weighing results can be achieved
under normal application conditions.
By selecting the correct location for your balance, you will be able to work quickly and
precisely.

Therefore please observe the following at the place of installation:

• 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 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 long periods of time.

Inadmissible bedewing (condensation of air moisture on the device) can occur if a
cold device is taken into a significantly warmer environment. In this case, please
acclimatise the device for approx. 2 hours at room temperature after it has been
disconnected from the mains.

• Avoid static charging of the material to be weighed and weighing container.

Major display deviations (incorrect weighing results) are possible if electromagnetic fields
occur, as well as due to static charging, currents and unstable power supply. It is then
necessary to change the location.

6.2 Unpacking

Carefully remove the balance from the packaging, remove the plastic cover and install the
balance in the intended workplace.

100 PRS/PRJ/ARS/ARJ-BA-def-0622

6.3 Installation

The balance consists of the balance body (1), the scale pan holder (4) and the pan (5),
which, depending on the model, may be square (fig. 1, right) or round (fig. 1, left).
Depending on the model (see Chapter 1 “Technical Data”) the balance additionally has a
simple windshield (fig. 1, right) or a windshield with sliding doors (fig. 1, left) (2) and/or a
protective ring (3).

Fig. 1 Your balance
Use the foot screws to level the balance until the air bubble is in the prescribed circle in

the spirit level.

PRS/PRJ/ARS/ARJ-BA-def-0622 101

6.3.1 Windshield for PRS and PRJ balances (d=0.1 mg)

The position of the windshield on the
balance can be seen in figure 1 (see 2a).

Note:
If the windshield is not even after assembly,

it can be adjusted according to drawing
below.

Press down the higher corner (arrow) with
moderate force.

If necessary, turn windshield by 90° and
carry out the same operation again until the
windshield sits evenly.

102 PRS/PRJ/ARS/ARJ-BA-def-0622

6.4 Functions of the balance

The versatile weighing program allows you to use the KERN balances of the PRS, PRJ,
ARS, ARJ series not only for simple weighings but also using a simple method to carry
out various weighing applications such as, for example, percentage or component
counting applications and documenting the measurements obtained accurately and
unequivocally.

The most important basic production features of the KERN PRS, PRJ, ARS, ARJ series
include:

• Anti-theft encoding with four-digit numerical code

• Multi-stage password protection for the program menus

• ICM-Autocalibration (Intelligent Calibration Mode)

• 5-key multifunction control panel

• LCD display with multi-line display

• ISO and GLP compliant reporting of measurement results

• RS232/V24 serial interface for data transfer

• Storable user-configuration (UMM User Menu Memorized)

• Functions programmed in the factory for:

 Parts counting
 Percentage weighing
 Weighing in different, internationally-valid units
 Density determination
 Net-total weighing function

• Device for suspended weighing

PRS/PRJ/ARS/ARJ-BA-def-0622 103

6.5 Equipment overview:

1 Cover of the device for suspended weighings
2 Name plate
3 Adjustable feet (for levelling)
4 Weighing plate
5 Multifunction display
6 10-key control panel
7 Serial No. plate
8 Connecting socket for power adaptor
9 RS232 Interface
10 Spirit level
11 Eyelet for attaching a safety chain

104 PRS/PRJ/ARS/ARJ-BA-def-0622

6.6 Scope of delivery

Inspect delivery for completeness immediately on unpacking all components.

d = 0,1 mg d = 1 mg

d = 10 mg

d = 0,1 mg d = 1 g

Standard accessories
Balance
Scale pan support with weighing plate
Power adaptor
Protective cover for the display
Windshield BASIC

(only balances d = 0.1 mg)
Simple windshield

(only balances d = 1 mg)
Protective ring

(only balances d = 1 mg, d = 10 mg)
Operating instructions

PRS/PRJ/ARS/ARJ-BA-def-0622 105

6.7 Mains supply

Electric power supply is by means of the external power adaptor. The printed voltage
level must comply with the local voltage.
Only use original KERN power adaptors. The use of other makes is subject to approval by
KERN.

6.8 Connecting peripheral devices

The balance must be disconnected from the mains before connecting or disconnecting
additional equipment (printer, PC) to or from the data interface.
Only use KERN accessories and peripheral devices with your balance as these have
been specially adapted to function best with your balance.

6.9 Commissioning

A warm up time of 1 hour after switching the balance on will stabilise the measuring
values.
The accuracy of the balance depends on the local gravity.
Please be sure to observe the information in the chapter on Calibration.

6.10 Calibration

Since the Earth's gravity is not the same everywhere, each balance must – in accordance
with the underlying physical weighing principle – be adjusted to compensate for the
gravity at each location. This adjustment process, known as “calibration”, must be carried
out on commissioning and after each subsequent relocation. It is also advisable that you
adjust the balance periodically during weighing operation in order to obtain exact
measured values.

NOTE

The balance must be calibrated on commissioning and after every relocation.
If you work in accordance with “Good Laboratory Practice GLP”, observe the prescribed

intervals between calibrations (adjustments).

Adjusting the calibration is carried out in the configuration menu. Depending on the model
of balance, this may be done externally, internally or automatically (see Chapter 8.6
“Calibration functions”).
Adjustment should be carried out with the recommended adjusting weight (KERN
ARS/PRS, see Chapter 1 „Technical Data“). The adjustment can also be carried out with
different adjusting weights, but not ideal from a metrological point of view.
Using the “Intelligent Calibration Mode” (ICM) the balance can itself determine the size of
the calibration weight, which enables an exact calibration with different weights (in 10 g,
50 g, 100 g and 500 g steps, depending on model).

You can find information about test weights on the Internet: http://www.kern-sohn.com

106 PRS/PRJ/ARS/ARJ-BA-def-0622

The calibration of the balance is set in the configuration menu (see Chapter 8.6
“Calibration of the balance”).

Possible types of calibration, depending on the balance model:

• External calibration by means of ICM (Intelligent Calibration Mode)

• External calibration with freely selectable weight

• Internal calibration

• Automatic calibration

NOTE

The calibration can be interrupted at any time by pressing the “ON/OFF” key.

6.10.1 External calibration b y means of ICM
(only ARS/PRS models)

Depending on the type of balance, calibration weights in steps of 10 g, 50 g, 100 g and
500 g can be used, where the calibration weight must relate to the accuracy of the
balance.
For an external calibration by means of ICM, “SET CALIBRATION MODE EXTERNAL”
must be selected in the configuration menu (see Chapter 8.6 “Calibration functions”).

• Switch to “WEIGHING” using the “ ” key

CALIBRATION

• Press “CAL” until “CALIBRATION” appears.

- - 0000 g

• The balance carries out a zero measurement
(0000 g is shown flashing)

- - 2000 g

• After the zero measurement has been taken,
the display flashes with the recommended
calibration weight

• Place the calibration weight on the pan

- - 2000 g

• The display continues to flash

• Calibration is complete when the display

stops flashing

+ 2000 g

PRS/PRJ/ARS/ARJ-BA-def-0622 107

6.10.2 External calibration with freely selectable weight

(only ARS/PRS models)

For an external calibration with user-definable weight, “SET CALIBRATION MODE EXT.­DEF.” must be selected in the configuration menu (see Chapter 8.6 “Calibration
functions”).
Then, the effective value of the calibration weight (DEF. n.nnn g) must be entered with up
to ten times precision when compared with the balance.

NOTE

If calibration is carried out with the free weight, then only this weight may be used.

Then proceed as follows:

• Switch to “WEIGHING” using the “ ” key

CALIBRATION

• Press “CAL” until “CALIBRATION” appears.

- - 0000 g

• The balance carries out a zero measurement
(0000 g is shown flashing)

- - 372 g

• After the zero measurement has been taken,
the display flashes with the previously
entered calibration weight

• Place the calibration weight on the pan

- - 372 g

• The display flashes rapidly

• Calibration is complete when the display

stops flashing (the exact weight is shown)

+372.15 g

108 PRS/PRJ/ARS/ARJ-BA-def-0622

6.10.3 Internal calibration
(only ARJ/PRJ models)

For an internal calibration with the built-in calibration weight, “SET CALIBRATION MODE
INTERNAL” must be selected in the configuration menu (see Chapter 8.6 “Calibration
functions”).

Then proceed as follows:

• Switch to “WEIGHING” using the “ ” key

• Press “CAL” until “CALIBRATION” appears.

• The calibration is finished after a certain period of time.

6.10.4 Automatic calibration

(onl

y ARJ/PRJ models)

For automatic calibration with the built-in calibration weight, “SET CALIBRATION MODE
AUTO” must be selected in the configuration menu (see Chapter 8.6 “Calibration
functions”).

The balance now calibrates itself automatically every 24 hours and/or after each
temperature change of 3 degrees Celsius, depending on how “SET CALIBRATION
AUTOCAL” has been defined in the configuration menu.

The timing of the automatic calibration is as determined in the configuration menu under
“SET CALIBRATION AUTOCAL.-TIME n h”. (e.g. 6 h for 06.00 o'clock in the morning).

NOTE

For automatic calibration by time and by time/temp., the date and time of the balance must
first be set correctly (see Chapter 8.9 “Date and time”).

The calibration can also be initiated manually at any time, even when auto-calibration is
activated.

The automatic calibration then takes place only if no weight is placed on the pan for at
least five minutes.

It is recommended that the time for the auto-calibration be set at a time outside the normal
business hours (for example, in the early morning).

PRS/PRJ/ARS/ARJ-BA-def-0622 109

6.10.5 Balances appropriate for verification (only ARJ/PRJ models)

Balances appropriate for verification are provided with EU/OIML approval or meet the EU
regulations for verified balances.
The balance program and certain functions of the weighing output differ from the standard
program in the case of balances which are appropriate for verification – in accordance
with EU regulations.

General:
According to EU guideline 90/384/EEC, balances must be verified officially if they are to
be used as follows (in a legally regulated area):

a) For commercial transactions if the price of goods is determined by weighing.
b) For the production of medicines in pharmacies as well as for analyses in the

medical and pharmaceutical laboratory.
c) For official purposes.
d) For the production of packed goods.

In case of doubt, please contact your local weights and measures office.
Verification information
For those balances marked as appropriate for verification in the technical data, an EC
type approval is available. In the event that the balance is used in an area subject to
verification as described above, it must be officially verified and re-verified at regular
intervals.
Re-verification of a balance is carried out in compliance with the respective legal
provisions of that particular country. The period of verification validity for balances in
Germany, for example, is normally 2 years.
The legal provisions of the country of use are to be observed.
After the verification process, the scale is sealed at the marked points.

Without the “seal”, the verification of the scale is not valid.

Balances appropriate for verification are provided with EU approval or meet the EU
regulations for verified balances.
The balance program and certain functions of the weighing output differ from the standard
program in the case of balances which are appropriate for verification – in accordance
with EU regulations.

NOTE

If a circle appears in the main display of a verified balance, then the displayed value is not
verified.

In balances of class (I) the circle also denotes the warm-up phase.
Your KERN trader will be happy to assist you at any time if you have any questions on the

verification of the balance or on working with verified balances.

110 PRS/PRJ/ARS/ARJ-BA-def-0622

6.10.6 Position of verification safety seal (only on ARJ/PRJ models appropriate
for verification)

M sign for EU – first calibration

(green M)

Balances which are subject to verification must be taken out of operation
if:

- The weighing result from the balance is outside the operational error limit.

Therefore at regular intervals, load the balance with known test weights
(approx. 1/3 of the maximum load) and compare with the display value.

- The re-verification date has been exceeded.

S Safety seals

(self-sticking seal or lead)
K shield of mark with CE-sign and date

of the year

M sign for EU – first calibration
(green M)

Interface