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
Service manual
Analytical balances
KERN AEJ/AES
Version 1.0
4/2009
GB
AEJ/AES-SH-e-0910
1
GB
KERN AEJ/AES
Version 1.0 4/2009
Service manual
Analytical balances
Table of Contents
1 Basic information.............................................................................................. 3
2 Total View........................................................................................................... 4
3 Electric/Electronic Construction......................................................................5
3.1 Block Diagram ........................................................................................................5
3.2 Whole Wiring...........................................................................................................6
4 Troubleshooting................................................................................................ 7
4.1 Troubleshooting Procedure...................................................................................7
4.2 Troubleshooting Table...........................................................................................8
4.3 Primary Check.......................................................................................................10
4.4 Check of Electric/Electronic Parts......................................................................11
5 Adjustment and Setting.................................................................................. 13
5.1 Span Calibration (Adjustment with internal weight – AEJ) ..............................13
5.2 Span Calibration (Adjustment with external weight – AES).............................14
5.3 Verification switch and seals ..............................................................................15
5.4 Corner Error Adjustment .....................................................................................16
5.5 Linearity Adjustment............................................................................................17
5.5.1 Linearity Adjustment of AES 120-4 and AEJ 120-4M...................................................... 17
5.5.2 Linearity Adjustment of AES 220-4 and AEJ 220-4M...................................................... 18
5.6 Calibration of Built-In Weight (Ref Cal) – only AEJ...........................................19
5.7 Address Data Check and Re-setting...................................................................20
5.8 Adjustment of Overload Stopper ........................................................................22
6 Parts Replacement.......................................................................................... 23
6.1 How to Remove the Case.....................................................................................23
6.2 The Sequence of HT-DP Board Replacement....................................................24
6.3 The Sequence of Mechanical Unit Replacement...............................................26
6.4 The Sequence of Tuning-Fork Sensor................................................................29
7 Parts List.......................................................................................................... 30
7.1 Explosion Diagram...............................................................................................30
7.2 Bill of Material.......................................................................................................31
8 Appendix.......................................................................................................... 32
2
1 Basic information
Grundlegende Hinweise
The device must be repaired only by trained specialist staff or personnel with
professional formation (such as a repair-specialist accredited by law
concerning verification).
The service manual is obligatory for repair work.
After repair, original conditions of the device have to be restored.
Only original spare parts should be used.
Instructions about conformity-evaluated scales
:
Repair must be carried only at 100% compliance with the type approval.
A violation of this specification will result in a loss of the type approval!
After successful repair the balance will have to be reverified before it can be
used again in a statutorily regulated field.
Das Gerät darf nur von geschultem oder beruflich ausgebildetem
Fachpersonal (z. B. eichrechtlich anerkannter Instandsetzer) repariert werden.
Die Serviceanleitung ist bindend für Reparaturen.
Das Gerät muss nach erfolgter Reparatur wieder in den Originalzustand
zurückversetzt werden.
Es dürfen nur Originalersatzteile verwendet werden.
Hinweis zu konformitätsbewerteten Waagen:
Reparatur darf nur in 100% -iger Übereinstimmung mit der
Bauartzulassung erfolgen. Ein Verstoß gegen diese Vorgabe führt zum Erlöschen
der Bauartzulassung!
Nach erfolgreicher Reparatur muss eine Nacheichung erfolgen, um die Waage
wieder im gesetzlich geregelten Bereich verwenden zu können.
3
2 Total View
Windshield
Weighing plate
Protection ring
Air bubble
LCD display
RS 232 interface
Printer interface
Connection mains adapter
Foot screw
Underfloor
weighing device
Foot
4
3 Electric/Electronic Construction
3.1 Block Diagram
Calibration Weight Unit
(AEJ only)
PRINT
5
3.2 Whole Wiring
Calibration Weight Unit
(AEJ only)
PRINT
6
4 Troubleshooting
4.1 Troubleshooting Procedure
7
4.2 Troubleshooting Table
SYMPTOMS CAUSES & REMEDY
No display lights on.
1. HT-DP board is defective.
2. AC adaptor is defective.
3. Inner connecting cord is not properly connected.
[
u - Err ] or [ o - Err ] appears
on the display.
1. Wrong weighing pan is applied.
2. Tuning-fork sensor or mechanical unit is
defective.
3. HT-DP board is defective.
4. Setting of address data has mistake.
5. Coefficient memories (address data) have
changed by noise or static electricity. Re-set the
address data and/or adjust the linearity.
Display does not get settled down.
Display does not repeat correctly.
Zero point drifts.
1. Some parts such as stopper touch others.
2. Weighing pan touch other parts.
3. Foreign substances are in the scale.
4. Tuning-fork sensor or mechanical unit is
defective.
5. Affected by wind or disturbing oscillation.
[
o - Err ]
appears with net load less
than
full capacity.
1. Gross weight applied to the scale pan (net weight
+ tare value) exceeds the scale capacity.
2. Setting of address data has mistake.
3. Coefficient memories (address data) have
changed by noise or static electricity. Re-set the
address data and/or adjust the linearity.
4. Wrong external weight is used in the span
calibration.
Span error is too much.
1. Tuning-fork sensor or mechanical unit is
defective.
2. HT-DP board is defective.
3. Setting of address data has mistake.
4. Coefficient memories (address data) have
changed by noise or static electricity. Re-set the
address data and/or adjust the linearity.
Non-linearity is too much.
1. Tuning-fork sensor or mechanical unit is
defective.
2. Setting of address data has mistake.
3. Coefficient memories (address data) have
changed by noises or static electricity. Re-set the
address data and/or adjust the linearity.
4. Wrong external weight is used in span
calibration.
8
SYMPTOMS CAUSES & REMEDY
Corner Error is too much.
1. Mechanical unit is defective. Leaf spring is bent
or twisted.
2. Pan base touch other parts.
Display suddenly disappeared.
1. HT-DP board is defective.
2. AC adaptor is defective.
or
appears.
1. HT-DP board is defective.
2. Coefficient memories (address data) have
changed by noises or static electricity. Re-set the
address data and/or adjust the linearity.
appears.
1. The weight of reference sample is too light (%
mode, counting mode).
appears.
1. Wrong external weight is used in span calibration
(external weight must be more than 50% of
scale capacity).
appears.
1. Span error exceeds 1% of scale capacity in
span calibration. Check the external weight.
appears.
1. During calibration there was a weight on the
weighing plate. Remove it from the pan.
appears.
1. Span error exceeds 1% of capacity in automatic
span calibration.
appears.
1. Interval time is not properly set.
appears.
1. Internal clock is defective. Check internal clock
and replace HT-DP board, if necessary.
[
r - Err ] appears.
1. The weight error exceeds ±100.00mg. Re-set the
weight error within ±100.00mg
[
A - Err ] appears.
1. Internal calibration automatics defective
appears.
1. Wrong operation in Cumulate Function or Net
Addition Function.
9
4.3 Primary Check
1. Is there any wind around the site? Is there any oscillation?
2. Is anything under the pan base or the weighing pan?
balance nor under pan/pan base.
When you attach or remove pan,
pan base, windshield, take care no
dust and/or liquid gets into the
Pan base
Pan
3. Is the weighing pan the right one?
4. Is the windshield properly attached?
5. Is the working table stable?
6. Is the balance installed in level?
Position of the air
bubble in the level
Adjuster
7. Is the AC adaptor properly connected both with scale and with outlet?
AC adapter connector
10
4.4 Check of Electric/Electronic Parts
1. Check of HT-DP board
11
2. Check of input voltage
TP0 – CN1-1 +9V~ +14V
3. Power voltage in the circuit
TP0 – TP1 +4.75V~ +5.25V
TP0 – TP2 +3.15V~ +3.45V
TP0 – IC12-O +7.6V~ +8.4V
TP0 – IC13-OUT +2.65V~ +2.95V
TP0 – D3 kasode +2.0V~ +2.4V
TP0 – IC8-5 -8.4V~ -7.6V
4. Check of signal wave
TP0 – IC1-39 (19.968MHz)
TP0 – TP4 (38.4MHz)
Check of tuning-fork vibration (800~1000Hz)
CH1: TP0 – TP6 P-P 200mv or more
CH2: TP0 – TP5 P-P 9V or more
12
5 Adjustment and Setting
5.1 Span Calibration (Adjustment with internal weight – AEJ)
Procedure for adjustment (according to the operating instructions):
Observe stable environment conditions. A warming-up time of approx. 8 hours for
stabilisation is necessary.
Function menu 1 setting: [ ]
x CA. 1
Ö Press the CAL key
AWT. CAL
CAL
PWSH C
CAL
Ö Press the CAL-key again and adjustment will take
place automatically.
AWT. CAL
CAL
CH. O
1
CAL
CH. F.S.
1
CAL
Ö The process of adjustment is completed.
Adjustment protocols will be issued automatically
if you connect an optional printer, see chpt. 15
“printer mode”. Whilst printing is in progress [busy
] will be displayed.
EnD
CAL
Ö The balance returns automatically into weighing
mode.
13
5.2 Span Calibration (Adjustment with external weight – AES)
Procedure for adjustment (according to the operating instructions):
Observe stable environment conditions. A warming-up time of approx. 8 hours for
stabilisation is necessary.
Function menu 1 setting:
x CA. 3
Recommended adjustment weight:
AES 120-4: 100g (E1) AES 220-4: 200g (E1)
Ö Press the CAL key
EHT.CAL
CAL
1
K
PWSH C
CAL
Ö Press the CAL-key again; zero point will be
saved.
EHT.CAL
CAL
1
K
Qn. O
CAL
Ö When display [on F.5] appears, put the adjusting
weight carefully in the centre of the weighing pan.
CAL
Qn
F.5.
Ö The adjustment process is started
CAL
Qn
F.5.
Ö The process of adjustment is completed.
Adjustment protocols will be issued automatically
if you connect an optional printer, see operating
instructions. Whilst printing is in progress
[busy ] will be displayed.
BWSX
CAL
EnD
CAL
Ö The balance returns automatically into weighing
mode.
Take away adjustment weight.
14
5.3 Verification switch and seals
Prior to verification you will have move the calibration switch to verification position
(See direction of arrow, fig. 1). In this position the display shows a bracket around the
last display point.
After verification the balance is sealed at the indicated positions.
Seal of approval Seal of approval
Fig. 1
Move verification switch to
verification position.
Seal/rubber plug/verification switch
Access to the verification switch is achieved
by removing the possibly existing seal (verification becomes invalid) and the rubber
plug.
Position of
verification switch
Status
forwards
Balance is unlocked for the adjustment process, adjustment will be possible "ADJ" appears when the balance is switched on.
backwards Verification position - Adjustment locked
15
5.4 Corner Error Adjustment
1. Turn the adjusting legs to bring the bubble of the level to the center of the
circle.
2. Put the full scale weight at “A” and push TARE key.
3. Move the weight to B and C. To adjust bolts R and L referring to the table
below so that the corner error is within the specified range.
基準点
C A
＋
<corner error adjustment table>
B
＋: Error is positive to the center
－: Er r or is n eg a ti v e to t h e c en te r
Drive the bolt clockwise
Drive the bolt counter-clockwise
Bolt L Bolt R
Di s pl a y
A
B
C
L R
+
－
Di s pl a y
A
B
C
L R
－
－
Di s pl a y
A
B
C
L R
－
＋
Di s pl a y
A
B
C
L R
＋
＋
16
5.5 Linearity Adjustment
Set the verification switch to unlocked before doing the linearity adjustment (see
chapter 5.3).
Prior to verification, the verification switch must be moved into the verification
position.
5.5.1 Linearity Adjustment of AES 120-4 and AEJ 120-4M
1. While pressing both + , press to switch on the balance.
Release both keys when [ Ht00x ] appears (maintenance mode).
2. After a while, display changes to weight value (not the zero point).
Press until appears after displaying .
3. While pressing first, press together and release both.
4. starts blinking to indicate zero adjustment is performed
automatically.
5. When display changes to blinking, put the external weight on
the pan according to the table below ( ~ ).
6. When display appears , press key. The display changes to
and returns to normal weighing mode.
AES / AEJ – 120g
additional loaded weight
(accumulated load)
0g (0g)
30g (30g)
30g (60g)
30g (90g)
30g (120g)
17
5.5.2 Linearity Adjustment of AES 220-4 and AEJ 220-4M
1. While pressing both + , press to switch on the balance.
Release both keys when [ Ht00x ] appears (maintenance mode).
2. After a while, display changes to weight value (not the zero point).
Press until appears after displaying .
3. While pressing first, press together and keep pressing both.
When appears, release both keys.
4. While pressing first, press together and release both.
5.
starts blinking to indicate zero adjustment is performed
automatically.
6. When
appears, put the external weight of 100g on weigh-
ing pan. The display changes to , put additional 120g (220g
in accumulate) on weighing pan.
7. appears again. Remove 120g (100g remains on the pan).
The display changes to . Remove 100g (nothing on the pan).
8. When display changes to blinking, put the external weight on
the pan according to the table below ( ~ ).
9. The display changes to and returns to normal weighing mode.
AES / AEJ – 220g
additional loaded weight
(accumulated load)
0g (0g)
50g (50g)
50g (100g)
50g (150g)
50g (200g)
20g (220g)
18
5.6 Calibration of Built-In Weight (Ref Cal) – only AEJ
1. Hold key while key is pressed until [FWnm 2] is displayed
(function menu 2). Release both keys.
Set and press the key to display
2. While pressing first, press together and release both. After
a while starts blinking.
3. When appears, put the external weight of full capacity on
weighing pan (max. 120g= 120g / max. 220g= 220g).
4. starts blinking. The display changes to after
displaying .
5. Remove external weight from the pan.
6. The display changes .
When internal calibration is successfully completed,
appears
on the display.
7. Press
key to return to normal weighing mode.
19
5.7 Address Data Check and Re-setting
a. Why do you need to re-set the address data, and in which case?
“Address data” (coefficient memories) sometimes changes by noise in the
environment or by static electricity. You can re-set the address data so as to bring back
the balance to the initial factory condition.
Re-set
address data
Span
Address data
(coefficient memories)
changed
Calibration
Primary
Check
You can find the address data sheet on the bottom of the balance.
data sheet
How to read the address data sheet
S=81S073 P=AJ0004 3003
00-9A,57,41,98,22,12,9B,32
08-85,19,30,00,27,56,62,80
10-00,18,27,39,26,72,17,12
18-99,72,27,8D,49,27,61,48
20-84,33,77,69,92,20,20,00
28-00,00,20,10,00,00,00,0A
30-06,07,02,0B,07,00,00,FF
38-1C,0B,14,53,0A,00,00,00
40-00,00,00,00,00,00,00,00
48-00,00,5F
左からAdr.00 ～ 07
左からAdr.08 ～ 0F
左からAdr.10 ～ 17
左からAdr.18 ～ 1F
左からAdr.20 ～ 27
左からAdr.28 ～ 2F
左からAdr.30 ～ 37
左からAdr.38 ～ 3F
左からAdr.40 ～ 47
左からAdr.48 ～ 4A
音叉番号
プログラム番 号
Number of
(see 5-1 / 5-2) (see 4-3)
From left to right : Add. 00~07
From left to right : Add. 48
~4A
From left to right : Add. 40
~47
From left to right : Add. 38~3F
From left to right : Add. 28~2F
From left to right : Add. 30
~37
From left to right : Add. 18
~1F
From left to right : Add. 20~27
From left to right : Add. 08~0F
From left to right : Add. 10~17
Tuning fork
Program number
20
b. How to re-set the address data
1. While pressing both + , press to switch on the balance.
Release both keys when [ Ht00x ] appears (maintenance mode).
2. After a while, display changes to weight value (not the zero point).
Press and hold until appears after displaying .
Press and hold again until appears.
Press key once.
3. The first address data (Addr. Number 00) is displayed.
data
addr. no.
4. Press key, appears. Every time is pressed, the
numerical number changes as .
Example : To set at addr. No. , select as the first step.
5. Press once, then numerical number ( in this case) shifts to upper digit.
. Set numerical number by pressing the key once.
6. Press
to display a numerical number at the right side.
7. Press key to select in the right side. By pressing key you set
in addr. and move to next address.
8. Input other data by the same procedure. When you set data in all the address,
the balance returns to normal weighing mode.
• Even after you set all data and return to weighing mode, the balance is still in
the maintenance mode. In order to exit from the maintenance mode, please
turn the power switch OFF.
• If you want to stop address data setting, you push and return to weighing
mode in the maintenance mode.
21
5.8 Adjustment of Overload Stopper
1. Enter “maintenance mode”. (see 5-5).
2. Put “stopper adjustment block” on the mechanical unit referring to the picture.
3. Adjust the level of the balance.
Stopper adjustment
block
4. Lose stopper fixing screw on the side of mechanical unit.
5. Press and check whether the indication is stable.
6. Adjust the stopper by sliding the stopper (the stopper should slightly touch with
guide-link)
7. Fix the stopper fixing screw
Stopper fixing screw
22
6 Parts Replacement
6.1 How to Remove the Case
1. Remove the weighing pan and pan base.
Weighing Pan
Pan Base
2. Remove the WS Ring by turning it counter-clockwise.
WS Ring
3. Remove the windshield.
4. Remove the upper case.
23
6.2 The Sequence of HT-DP Board Replacement
1. How to replace HT-DP board
a. Remove the case referring to chapter 6-1.
b. Remove wires to tuning-fork sensor by welding solders at HT-DP board.
c. Loose and remove fixing screws.
d. Pull out all connectors, and remove HT-DP board.
e. Solder wires of tuning-fork sensor to HT-DP board.
White
White
Black
G
G
G
f. Plug connectors.
g. Place HT-DP board on the chassis, and fix the screws.
24
2. Adjustment after the replacement of HT-DP board
Replacement with new
HT-DP board
Address data re-setting
Span Calibration
Linearity Adjustment
See 5.7
See 5.5
See 5.1 / 5.2
See 4.3
See 5.6
Calibration of internal
weight (AEJ only)
Performance check
25
6.3 The Sequence of Mechanical Unit Replacement
1. How to remove the mechanical unit
a
a. Open the case and remove nylon cramp fixing
the connector cables.
b. Pull out RS cable from LF board (power source board).
b
c
c. Loose four screws, and remove the sensor cover.
sensor cover
d. Attach “mono-metal fixing block” to the
mechanical unit.
e. Loose two bolts fixing the weight stay,
and remove the weight stay.
Weight stay
d
e
Sensor cover
Mono-metal fixing
block
26
f. Pull out the connectors and remove HT-DP board.
f
g. Remove internal weight ASSY first, and
then remove span weight.
span weight
g2
g1
internal weight
ASSY
h. Loose three screws, and remove
the mechanical unit.
h
27
2. How to install the mechanical unit
*please refer to the pictures in “How to remove the mechanical unit”.
a. Attach the “mono-metal fixing block” to the mechanical unit
b. Put the mechanical unit in the chassis (torque:20kgfcm)
c. Install the span weight.
d. Connect the connector cables to HT-DP board and attach HT-DP board to the
lower case.
e. Remove “mono-metal fixing block” form the mechanical unit.
f. Install the weight stay.
g. Put the sensor cover.
h. Connect RS cable to LF board (power source board) and attach the nylon cramp.
3. Adjustment after the replacement with new mechanical unit
In case of any defection in the mechanical unit, the mechanical unit should be
replaced with new one. After the replacement with new mechanical unit, please make
following adjustment and setting:
Replacement with new
mechanical unit
Corner Error Adjustment
See 5.4
Calibration of internal
weight (AEJ only)
Span Calibration
Adjustment of overload
stopper
Performance check
Linearity Adjustment
See 5.5
See 5.6
See 5.1 / 5.2
See 5.8
See 4.3
28
6.4 The Sequence of Tuning-Fork Sensor
1. How to replace the tuning-fork sensor
1. Remove the mechanical unit from the chassis (see 6.3). Leave “mono-metal
fixing block” attached to the mechanical unit.
2. Loose two bolts and remove the tuning-fork sensor.
3. Install new tuning-fork sensor to the mechanical unit with two bolts (torque:
20kgfcm).
4. Install the mechanical unit to the chassis (see 6.3).
2. Adjustment after the replacement of tuning-fork sensor
Replacement with new
mechanical unit
Corner Error Adjustment
See 5.4
Calibration of internal
weight (AEJ only)
Span Calibration
Adjustment of overload
stopper
Performance check
Linearity Adjustment
See 5.5
See 5.6
See 5.1 / 5.2
See 5.8
See 4.3
29
7 Parts List
7.1 Explosion Diagram
30
7.2 Bill of Material
POS. NO.
DESCRIPTIONS
PARTS
NO.
Q'TY REMARKS
1
LOWER
CASE
270002I
1
2
A
DJUSTER
AJM
200034I
1
3
SHUTTER
3190P
1
4
TM-166-3
22OM016
1
6
HT-DP PCB ASSY.
27AE001
1
6-1
HT-LCDBL PCB ASSY.
27OE001
1
7
BATTERY CASE
270004I
1
8
HT-S PCB ASSY.
27AE002
1
9
HT-IO PCB ASSY.
27AE003
1
10
RS HOLDER
270007P
1
11
D-SUB CODE ASSY. 27AE010
1
12
SPACER
OM256
2
13
A
DJUSTER COVER
270003I
1
14
NYLON
RIVET NRP-355
22OM013
1
15
CAL WEIGHT HOLDER
270008
A
1
16
A
CAL WEIGHT
(L
)
270006C
2for
220g
capacity
model
16B CAL WEIGHT
(M
)
270007C
2for
120g
capacity
model
17
WEIGHT
STAY
270010P
1
18
UPPER
CASE
270001I
1
19
BASE PLATE
270002P
1
20
PANEL
270001P
1
21
CHASSIS ASSY.
270013I
1
22
LEVEL
ASSY
270015
A
1
23
A
NTI VIBRATION RUBBER
270002J
1
24
M5
Φ16
FLAT WASHER
MS0273
1
25
M5 NUT
M5NT1S
1
26
MECHANICAL ASSY.
270009
A
1
26-1 HT-220 TUNING FORK SENSOR
270010
A
1
27
SENSOR COVER
270012I
1
28
WINDSHIELD ASSY.
270003
A
1
29(28-1
)
WS TOP DOOR
270011I
1
30(28-2
)
WS SIDE DOOR
270010I
2
31
WS TOP PLATE
270005P
1
32
WS RING
270004P
1
33
PAN BASE ASSY.
270004
A
1
34
PAN SA
200173P
1
35
DUST COVER
ASSY
270005
A
1
36
A A
C
ADAPTOR UM103 UM103
1
36B
A
C
ADAPTOR UM106 UM106
1
31
8 Appendix
Table of Recommended Minimum Criteria for Adjustment
Repeatability *1 Corner Error *2 Non-Linearity
AES 120-4
AEJ 120-4M
0.0001g ±0.0005g ±0.0003g
AES 220-4
AEJ 220-4M
0.0001g ±0.0005g ±0.0003g
*1 standard deviation *2 1/3 of full capacity loaded
Repair Tool List
1. Mono-metal fixing block
2. Stopper adjustment block
32
Loading...