Precisa 390 Series User manual

Service Manual
—
Wartungsanleitung
390
Precision Balances
Präzisionswaagen

390
Precisa Gravimetrics AG 1
Identification – Identifikation
Service manual 390, Precision balances
Index --
July 2020
Subject to tec nical modifications
Wartungsanleitung 390, Präzisionswaagen
Index --
Juli 2020
Tec nisc e Änderungen vorbe alten
www.precisa.com
Copyright
No reproduction in any form of t is document, in w ole or in part, may be made wit out written
aut orization from Precisa Gravimetrics AG.
O ne sc riftlic e Gene migung der Precisa Gravimetrics AG darf diese Anleitung weder ganz noc
teilweise nac gedruckt oder vervielfältigt werden.
© Precisa Gravimetrics AG, 8953 Dietikon, Switzerland A. MMDCCLXX
O
A.V.C. ROMANVS EMONENSIS FECIT

390 Table of contents – In altsverzeic nis
Precisa Gravimetrics AG 2
Table of contents – Inhaltsverzeichnis
1 Components – Bestandteile ..................................................................................................... 3
1.1 About spare parts – Über Ersatzteile ............................................................................ 3
1.2 Balance groups – Waagengruppen ............................................................................... 3
1.3 Housing – Ge äuse .................................................................................................... 4
1.4 Main board – Hauptprint ............................................................................................. 6
1.5 Power adapter – Netzadapter ...................................................................................... 7
1.6 Power cables – Stromkabel ......................................................................................... 7
2 djustments .............................................................................................................................. 8
2.1 Before getting started ................................................................................................ 8
2.1.1 Table of specifications ................................................................................................ 8
2.1.2 Placing loads ............................................................................................................. 8
2.1.3 Operating notes ......................................................................................................... 8
2.2 Adjusting t e corner load (t e balance is closed) ........................................................... 9
2.2.1 Determining t e corner load values .............................................................................. 9
2.2.2 Preparing t e closed balance for corner load adjustment ................................................ 9
2.2.3 Adjusting t e corner load .......................................................................................... 10
2.3 Setting t e balance to t e service mode (t e balance is closed) .................................... 11
2.4 Adjusting t e linearity .............................................................................................. 11
2.5 S-correction ............................................................................................................ 12
2.5.1 Correcting t e S-curve of t e full range ...................................................................... 12
2.5.2 Correcting t e S-curve of t e full range (dual range balances only) ................................ 12
2.5.3 Notes on S-correction............................................................................................... 13
2.6 Adjusting t e internal reference weig t (CRW) ............................................................ 14
2.6.1 Adjusting t e internal reference weig t using a nominal weig t ..................................... 14
2.6.2 Adjusting t e internal reference weig t using a calibrated weig t .................................. 14
2.7 Adjusting t e balance using its internal reference weig t .............................................. 14
2.8 Adjusting t e draft s ield .......................................................................................... 15
2.9 Discussion wit t e manufacturer .............................................................................. 16
2.10 Sending t e balance to t e manufacturer for repairs .................................................... 16
3 Justierung ............................................................................................................................... 17
3.1 Vor dem Beginnen ................................................................................................... 17
3.1.1 Spezifikationstabelle ................................................................................................ 17
3.1.2 Lasten auflegen ....................................................................................................... 17
3.1.3 Bedienungs inweise ................................................................................................. 17
3.2 Die Eckenlast justieren (die Waage ist gesc lossen) ..................................................... 18
3.2.1 Die Eckenlastwerte bestimmen .................................................................................. 18
3.2.2 Die gesc lossene Waage zum Justieren der Eckenlast vorbereiten ................................. 18
3.2.3 Die Eckenlast justieren ............................................................................................. 19
3.3 Die Waage in den Servicemodus bringen (die Waage ist gesc lossen) ............................ 20
3.4 Die Linearität justieren ............................................................................................. 20
3.5 S-Korrektur ............................................................................................................ 21
3.5.1 Die S-Kurve des Grobbereic s korrigieren ................................................................... 21
3.5.2 Die S-Kurve des Feinbereic s korrigieren (nur Zweibereic swaagen) .............................. 21
3.5.3 Anmerkungen zur S-Korrektur ................................................................................... 22
3.6 Das interne Referenzgewic t justieren (CRW).............................................................. 23
3.6.1 Das interne Referenzgewic t mittels eines Nominalgewic ts justieren ............................ 23
3.6.2 Das interne Referenzgewic t mittels eines kalibrierten Gewic ts justieren ...................... 23
3.7 Die Waage mittels i res internen Referenzgewic ts justieren ........................................ 23
3.8 Den Windsc utz justieren ......................................................................................... 24
3.9 Rücksprac e mit dem Hersteller ................................................................................ 25
3.10 Die Waage zur Reparatur an den Hersteller sc icken .................................................... 25

390 Components – Bestandteile
Precisa Gravimetrics AG 3
1Components – Bestandteile
1.1 bout spare parts – Über Ersatzteile
•Certain spare parts ave to be determined more precisely because of t e various capacities of
balances. T erefore refer to t e following table and find out to w ic group a balance belongs.
Example: A 220A belongs to group A2. Thus, in group specific spare parts select the ones of
group A2.
Bestimmte Ersatzteile müssen aufgrund versc iedener Tragfä igkeiten der Waagen nä er
bestimmt werden. Hierfür ist mit Hilfe der folgenden Tabelle erauszufinden, welc er Gruppe die
Waage ange ört.
Beispiel: Eine 220A gehört in die Gruppe A2. Bei gruppenspezifischen Ersatzteilen ist also
dasjenige der Gruppe A2 zu nehmen.
•N instead of an item number means "Not available as spare part".
N anstelle der Artikelnummer bedeutet «Nic t als Ersatzteil er ältlic ».
1.2 Balance groups – Waagengruppen
Group Model
A2 125SM 125SM-FR
125SM-DR
225SM-FR
225SM-DR
120A
220A
A3 320A
520A

390 Components – Bestandteile
Precisa Gravimetrics AG 4
1.3 Housing – Gehäuse

390 Components – Bestandteile
Precisa Gravimetrics AG 5
Pos. Pcs. Item number Item rtikel
1 1 390-2063 Bottom plate Bodenplatte
2 1 390-2064 Protective ring older Sc utzring alter
3 1 290-2035 Protective ring D80 Sc utzring D80
1 360-2016 Protective ring D90 Sc utzring D90
4 1 390-8002 Weig ing pan D80 Waagsc ale D80
1 390-8007 Weig ing pan D90 Waagsc ale D90
5 1 390-7023 Top glass slide Glassc ieber oben
6 1 390-7022 Side glass slide left Seitenglassc ieber links
7 1 390-7021 Side glass slide rig t Seitenglassc ieber rec ts
8 1 390-7020 Front glass Frontsc eibe
9 2 390-8009 Locking andle blue Verriegelungsgriff blau
10 1 390-7008 Driving carriage Mitne merwagen
11 1 390-7007 Terminal docking Terminalkopplung
12 2 390-8003 Infrared sensor Infrarotsensor
13 1 390-7079 Connection cable terminal Verbindungskabel Terminal
14 1 390-8004 Terminal Terminal
15 1 390-2007 Cable cover Kabelabdeckung
16 2 PN 1100-323 Round eaded bolt M3x6 Bec ersc raube M3x6
17 2 390-4005 Levelling foot Stellfuß
18 1 390-7070 Outer panel Außenblec
19 1 390-7039 Top panel Blec oben
20 1 390-7031 Hood Haube
21 8 PN 1100-325 Screw cap Torx M3x12 LT-Sc raube M3x12
22 1 PN 1053-024 Sealing plug D9.5-11 Versc lussstopfen D9.5-11
23 1 PN Display Anzeige
24 4 PN 1100-159 Screw cyl. P illips M3x16 Cr ZK-Sc raube M3x16 Cr
25 4 PN 1053-010 Rubber pad Gummipuffer

390 Components – Bestandteile
Precisa Gravimetrics AG 6
1.4 Main board – Hauptprint
Pos. Pcs. Item number Item rtikel
- 1 390-7056-020 Main board cpl., weig ing cell Hauptprint kpl., Wägezelle

390 Components – Bestandteile
Precisa Gravimetrics AG 7
1.5 Power adapter – Netzadapter
Pos. Pcs. Item number Item rtikel
- 1 PN 3953-005 Universal power adapter Universalnetzadapter
1.6 Power cables – Stromkabel
Sc uko Swiss type ‒ CH USA
UK AUS
Pos. Pcs. Item number Item rtikel
- 1 PN 3602-400 Power cable, Sc uko Stromkabel, Sc uko
- 1 PN 3602-401 Power cable, Swiss type Stromkabel, CH
- 1 PN 3602-402 Power cable, USA Stromkabel, USA
- 1 PN 3602-403 Power cable, UK Stromkabel, UK
- 1 PN 3951-021 Power cable, AUS Stromkabel, AUS

390 Adjustments
Precisa Gravimetrics AG 8
2djustments
2.1 Before getting started
2.1.1 Table of specifications
In carrying out t e following adjustments, it is necessary to know t e specifications of t e balance in
service. You may download t e specifications for servicing from our website: www.precisa.com. T e
following instructions refer often to t at specifications, ave a printout of t em always at disposal!
2.1.2 Placing loads
Place all loads always carefully and, unless ot erwise asked, in t e center of t e weig ing pan!
2.1.3 Operating notes
•Activities, suc as wiping gestures to be performed or ard keys, icons, buttons and menu items
to be pressed, are printed in bold.
•Hardkeys are in square brackets: [ON/OFF].
•Icons are in round brackets: (Linearization .
•Soft buttons are in curly brackets: {Adjust draft shield}.
•Wipe gestures and menu items are wit out brackets. In a pat t ey are separated from eac
ot er by a ">": Wipe left > (Settings > Adjustment > Adjustment mode > Automatic.

390 Adjustments
Precisa Gravimetrics AG 9
2.2 djusting the corner load (the balance is closed)
2.2.1 Determining the corner load values
1. Ensure t e balance as reac ed its operating temperature and is levelled and ave a box
spanner No. 5.5 ready.
2. Have, according to t e specifications, a suitable corner load reference weig t at disposal.
3. Place t e weig t in t e center T of t e weig ing pan and tare t e balance.
4. Place t e weig t in order in t e angles A. Every single value of A as to stay, according to t e
specifications, wit in t e tolerated range!
5. Skip all following corner load adjusting c apters if t e determined corner load values stay wit in
t e tolerated range.
2.2.2 Preparing the closed balance for corner load adjustment
1. Balances with ECS only: Lift t e retaining plate of t e ECS slig tly and pull it out carefully.
2. Remove t e two sealing plugs (22).
A
A
A
T
A

390 Adjustments
Precisa Gravimetrics AG 10
2.2.3 djusting the corner load
•T e difference from position T to L is adjusted wit t e left corner load screw L.
•T e difference from position T to R is adjusted wit t e rig t corner load screw R.
•Opening t e corner load screw, i.e. turning it counterclockwise , s ifts t e difference in
negative direction. T e displayed value relatively decreases.
•Closing t e corner load screw, i.e. turning it clockwise , s ifts t e difference in positive
direction. T e displayed value relatively increases.
Procedure
1. Ensure t e balance as reac ed its operating temperature, is levelled and set to t e weig ing
mode (turn t e balance off and on by pressing [ON/OFF] twice).
2. Place t e weig t on T, tare t e balance, slide t e weig t to L and calculate t e difference:
Δ
T

L
= L-T = L-0 = L [d]; (L = tared = 0); Example:
T

L
= L = +12d.
3. Place t e weig t on T, tare t e balance, slide t e weig t to R and calculate t e difference:
Δ
T

R
= R-T = R-0 = R [d]; (D = tared = 0); Example:
T

R
= R = -7d.
Important: Start adjusting t e side wit t e larger difference!
4. The difference T  L is larger and positive (+12d). Opening the corner load screw L
counterclockwise

shifts the difference in negative direction (+12 .. +11 .. +10 ..).
5. The difference T  R is smaller and negative (-7d). Closing the corner load screw R clockwise

shifts the difference in positive direction (-7 .. -6 .. -5 ..).
6. Keep reducing t e diagonal differences, until all four corner load deviations stay wit in t e
tolerated range. To determine t ese, see c apter 2.2.1 from step 3.
L
TL
R
TR
T
L
R
T
T = tared = 0

390 Adjustments
Precisa Gravimetrics AG 11
2.3 Setting the balance to the service mode (the balance is closed)
1. Connect t e balance to t e mains wit t e power adapter and turn it on.
2. Press t e service switc on t e rear of t e balance wit t e small exagon key. T e service
password input window appears.
3. Enter t e service code "5236". In t e eadline t e balance indicates "[Service]" and is in service
mode.
2.4 djusting the linearity
1. Ensure t e balance as reac ed its operating temperature, is levelled and set to t e service
mode according to c apter 2.3.
2. Have, according to t e specifications, suitable linearisation reference weig ts at disposal: 2×
alf load.
3. Wipe left > (Linearization .
4. Have t e weig ing pan empty and press {Measure zero load}. T e balance recognises t e
zero point and displays "Measuring zero ...".
5. Wait until t e zero load in t e info section appears as done, place t e first alf load and press
{Measure half load}. T e balance recognises t e first alf load and displays "Measuring alf
load ...".
6. Wait until t e alf load 1 in t e info section appears as done, remove t e first, place t e second
alf load and press {Measure half load} again. T e balance recognises t e second alf load
and displays "Measuring alf load ...".
7. Wait until t e alf load 2 in t e info section appears as done, place t e full load (bot alf loads
are placed now) and press {Measure full load}. T e balance recognises t e full load and
displays "Measuring full load ...".
8. Wait until t e full load in t e info section appears as done and press {Calculate & Store}. T e
balance sets t e linearity factors meanw ile it displays "Calculating". W en t is is done it s ows
t e info window wit t e eading "Linearization done" and asks w et er t e internal reference
weig ts s ould be adjusted.
9. If so (recommended!), empty t e weig ing pan and press {Yes}. T e balance starts adjusting
t e internal reference weig ts directly as if (Adjustment > {CRW} ad been called up, see
c apter 2.6.
If not, press {No}. T e balance s ows "Linearization Done".
Service switch

390 Adjustments
Precisa Gravimetrics AG 12
2.5 S-correction
Important: The instructions in this chapter assume that the linearity is adjusted!
Once t e linearity is adjusted, t is means t at t e balance is correct at zero, alf load and full load.
In t e remaining weig ing range, owever, t e balance response can follow a slig t S curve and
may need to be slig tly readjusted at one point or anot er. T is can be done by means of S
correction at 1/4 and 3/4 load, and additionally at 1/8 and 3/8 load on dual-range balances.
2.5.1 Correcting the S-curve of the full range
1. Ensure t e balance as reac ed its operating temperature, is levelled and set to t e service
mode according to c apter 2.3.
2. Wipe left > (MSP > Context menu > {S-correction}.
3. Have, according to t e specifications, suitable linearisation reference weig ts at disposal: 1×
alf load and 1× quarter load.
4. Tare t e balance, place t e quarter load and note t e displayed value.
5. Addittionally place t e alf load and note t e displayed value (t ree quarter load).
6. Calculate t e differences:
Δ
A
= quarter load
displayed
− quarter load
placed
Δ
B
= t ree quarter load
displayed
− t ree quarter load
placed
Example:
A
= 50.0005g − 50.0000g = 0.0005g
B
= 149.9997g − 150.0000g = −0.0003g
7. T e S-correction values correspond to t e differences determined above wit reversed sign in
digits [d]:
S
A
= −Δ
A
[d]
S
B
= −Δ
B
[d]
Example:
A
= 0.0005g = +5d ⇒ S
A
= −
A
= −5d
B
= −0.0003g = −3d ⇒ S
B
= −
B
= +3d
8. Enter t e determined S-correction values; S
A
for sector A (1/4), S
B
for sector B (3/4).
2.5.2 Correcting the S-curve of the full range (dual range balances only)
On dual range balances, t e S-curve can be straig tened bot in t e coarse and fine range.
Δ
A
Δ
B
0
1/2
1
A
1/4
3/4
B

390 Adjustments
Precisa Gravimetrics AG 13
After t is as already been done for t e coarse range, any remaining deviations can also be
corrected in t e fine range.
1. Ensure t e balance as reac ed its operating temperature, is levelled and set to t e service
mode according to c apter 2.3.
2. Wipe left > (MSP > Context menu > {S-correction}.
3. Have, according to t e specifications, suitable linearisation reference weig ts at disposal: 1×
quarter load and 1× eig t load.
4. Tare t e balance, place t e eig t load and note t e displayed value.
5. Addittionally place t e quarter load and note t e displayed value (t ree eig t load).
6. Calculate t e differences:
Δ
A1
= eig t load
displayed
− eig t load
placed
Δ
B1
= t ree eig t load
displayed
− t ree eig t load
placed
Example:
A1
= 25.00002g − 25.00000g = 0.00002g
B1
= 74.99999g − 75.00000g = −0.00001g
7. T e S-correction values correspond to t e differences determined above wit reversed sign in
digits [d]:
S
A1
= −Δ
A1
[d]
S
B1
= −Δ
B1
[d]
Example:
A1
= 0.00002g = +2d ⇒ S
A1
= −
A1
= −2d
B1
= −0.00001g = −1d ⇒ S
B1
= −
B1
= +1d
8. Enter t e determined S-correction values; S
A1
for sector A1 (1/8), S
B1
for sector B1 (3/8).
2.5.3 Notes on S-correction
•A correction of t e S-curve is actually a refined adjustment of t e linearity at additional points.
Correction values of up to 4, maximum 5 digits are t e normal case and s ould not be
exceeded. If t e measurements described above nevert eless result in ig er correction values,
t e error must be soug t elsew ere. T e most common cause is a damaged or incorrectly
tig tened flexure, w ic means t at t e weig ing cell must be over auled. Muc less frequently
it is due to t e main board or t e floating sensor.
•S-correction of t e fine range requires very accurate or calibrated weig ts, w ic can quickly
become tricky. In addition, experience as s own t at t e deviations are wit in t e repeatability
limits. To avoid t is, it is recommended t at t e weig ing cell be carefully over auled and t e
linearity adjusted in t e same way.
0
0
1/2
1/2
1
1
1/4
1/4
A1
1/8
B1
3/8
3/4
Δ
A1
Δ
B1

390 Adjustments
Precisa Gravimetrics AG 14
2.6 djusting the internal reference weight (CRW)
W en adjusting t e internal reference weig t, its mass is determined by comparison wit an
external reference weig t. If suc a reference weig t is available wit sufficient accuracy, t is can
be done wit a nominal weig t, as described in c apter 2.6.1. If t e accuracy of t e nominal weig t
is not sufficient, a calibrated weig t can be used, see c apter 2.6.2.
Note: W en setting to service mode, t e adjustment mode is set to Internal by default.
2.6.1 djusting the internal reference weight using a nominal weight
1. Ensure t e balance as reac ed its operating temperature, is levelled and set to t e service
mode according to c apter 2.3.
2. Have, according to t e specifications, a suitable full load reference weig t at disposal.
3. Wipe left > (Adjustment .
4. Have t e weig ing pan empty and press {CRW}. T e balance measures t e zero point, t e
internal reference weig t, again t e zero point displaying "CRW running ...". T en it requests
t e full-load weig t wit t e prompt "Place weig t ...".
5. Place t e ready full load weig t. T e balance measures t e placed full load weig t, determines
and sets t e adjustment factors and displays "CRW running ...". As soon as it is finis ed, it
displays "CRW successfully done". It is still in service mode.
Important: The internal reference weight is now adjusted, the balance not yet. It must be adjusted as
described in chapter 2.7.
2.6.2 djusting the internal reference weight using a calibrated weight
1. Ensure t e balance as reac ed its operating temperature, is levelled and set to t e service
mode according to c apter 2.3.
2. Have, according to t e specifications, a suitable full load reference weig t wit t e
corresponding calibration certificate at disposal.
Important: T e calibration certificate must still be valid and indicate t e conventional mass value
of t e weig t to at least one decimal place more accurate t an t e readability of t e balance.
3. Wipe left > (Settings > Adjustment > Adjustment mode > Externally defined and
Adjustment weight [g] > enter t e conventional mass value from calibration certificate.
4. {Home} > Wipe left > (Adjustment .
5. Have t e weig ing pan empty and press {CRW}. T e balance measures t e zero point, t e
internal reference weig t, again t e zero point displaying "CRW running ...". T en it requests
t e full-load weig t wit t e prompt "Place weig t ...".
6. Place t e ready full load weig t. T e balance measures t e placed full load weig t, determines
and sets t e adjustment factors and displays "CRW running ...". As soon as it is finis ed, it
displays "CRW successfully done". It is still in service mode.
Important: The internal reference weight is now adjusted, the balance not yet. It must be adjusted as
described in chapter 2.7.
2.7 djusting the balance using its internal reference weight
1. Ensure t e balance as reac ed its operating temperature, is levelled and set to t e weig ing
mode (turn t e balance off and on by pressing [ON/OFF] twice).
2. Wipe left > (Settings > Adjustment > Adjustment mode > Internal or Automatic >
{Home}.
3. Wipe left > (Adjustment > {Start}. T e balance adjusts itself using its internal reference
weig t displaying "Adjustment running...". As soon as it is finis ed, it will display "Adjustment
done.".

390 Adjustments
Precisa Gravimetrics AG 15
2.8 djusting the draft shield
1. Ensure t e balance is levelled and set to t e service mode according to c apter 2.3.
2. Wipe left > (MSP > {Adjust draft shield}. T e balance adjusts t e draft s ield
automatically displaying "Draft s ield adjustment running ...". W en t is is done it displays t e
info window "Adjustment done".

390 Adjustments
Precisa Gravimetrics AG 16
2.9 Discussion with the manufacturer
Important: Have at disposal t e following information in discussions wit t e manufacturer (device
information can be found on t e identification plate on t e side of t e balance or recalled by wiping
left > (Settings > About device > Device information):
•Series, e.g. 390
•Model, e.g. HF 125SM
•Seven-figure serial number, e.g. 8200005
•Terminal firmware, e.g. 1.1.1.2930213967, and its legally relevant ID, e.g. 1.0.1
•Sensor firmware, e.g. F00-0000.P11
•A precise description of t e circumstances, of ow t e failure occurred and of t e failure itself.
•Weig ing results
2.10 Sending the balance to the manufacturer for repairs
If a repair in t e field is not possible, t is can be done by t e manufacturer. For t is purpose, t e
balance must be sent to t e address below in its original packaging. Instead of forms, t e balance
must be accompanied by a printout of any e-mail correspondence and information as specified in
c apter 2.9.
Precisa Gravimetrics AG
Moosmattstrasse 32
CH-8953 Dietikon
Switzerland
P one [phone]
E-mail [e-mail]

390 Justierung
Precisa Gravimetrics AG 17
3Justierung
3.1 Vor dem Beginnen
3.1.1 Spezifikationstabelle
Folgende Justierarbeiten setzen die Kenntnis der Gerätespezifikationen voraus. Diese Spezifikationen
zur Wartung können von unserer Website eruntergeladen werden: www.precisa.com. Die folgenden
Anweisungen bezie en sic oft darauf. Diese Spezifikationen sind stets ausgedruckt griffbereit zu
alten!
3.1.2 Lasten auflegen
Wenn nic t anders verlangt, sind Lasten stets in die Mitte der Waagsc ale aufzulegen!
3.1.3 Bedienungshinweise
•Aktivitäten, wie auszufü rende Wisc gesten oder zu drückende Hardkeys, Icons, Buttons und
Menüpunkte, sind fettgedruckt.
•Hardkeys ste en in eckigen Klammern: [EIN/AUS].
•Icons ste en in runden Klammern: (Linearisierung .
•Buttons ste en in gesc weiften Klammern: {Windschutz justieren}.
•Wisc gesten und Menüpunkte ste en o ne Klammern. In einem Pfad sind sie durc ein «>»
voneinander getrennt: Nach links wischen > (Einstellungen > Justierung >
Justiermodus > Automatisch.

390 Justierung
Precisa Gravimetrics AG 18
3.2 Die Eckenlast justieren (die Waage ist geschlossen)
3.2.1 Die Eckenlastwerte bestimmen
1. Sic erstellen, dass die Waage ausnivelliert ist und i re Betriebstemperatur erreic t at; einen
Gabelsc lüssel Nr. 5.5 bereit alten.
2. Das laut den Spezifikationen passende Eckenlast-Referenzgewic t bereit alten.
3. Das Gewic t in die Mitte M legen und die Waage tarieren.
4. Das Gewic t der Rei e nac in alle Ecken E legen. Jeder einzelne Wert muss gemäß
Spezifikationen inner alb des tolerierten Bereic s liegen!
5. Liegen alle ermittelten Eckenlastwerte E inner alb des tolerierten Bereic s, alle folgenden
Kapitel über das Justieren der Eckenlast überspringen.
3.2.2 Die geschlossene Waage zum Justieren der Eckenlast vorbereiten
1. Nur Waagen mit ECS: Das Halteblec des ECS etwas an eben und vorsic tig erauszie en.
2. Die beiden Versc lussstopfen (22) entfernen.
E
E
E
M
E

390 Justierung
Precisa Gravimetrics AG 19
3.2.3 Die Eckenlast justieren
•Die Differenz von der Position T nac L wird mit der linken Eckenlastsc raube L justiert.
•Die Differenz von der Position T nac R wird mit der rec ten Eckenlastsc raube R justiert.
•Das Öffnen der Eckenlastsc raube, also das Dre en derselben im Gegenu rzeigersinn ,
verrückt die Differenz in die negative Ric tung. Der angezeigte Messwert nimmt relativ ab.
•Das Sc ließen der Eckenlastsc raube, also das Dre en derselben im U rzeigersinn , verrückt
die Differenz in die positive Ric tung. Der angezeigte Messwert nimmt relativ zu.
Vorgehen
1. Sic erstellen, dass die Waage ausnivelliert ist, i re Betriebstemperatur erreic t at und sic im
Wägemodus befindet (Mit [ON/OFF] aus- und wieder einsc alten).
2. Das Gewic t auf T legen, die Waage tarieren, das Gewic t nac L sc ieben und die Differenz
berec nen:
Δ
T

L
= L-T = L-0 = L [d]; (L = tariert = 0); Beispiel:
T

L
= L = +12d.
3. Das Gewic t auf T legen, die Waage tarieren, das Gewic t nac R sc ieben und die Differenz
berec nen:
Δ
T

R
= R-T = R-0 = R [d]; (D = tariert = 0); Beispiel:
T

R
= R = -7d.
Wichtig: Mit dem Justieren auf der Seite mit der größeren Differenz beginnen!
4. Die Differenz T  L ist größer und positiv (+12d). Ein Öffnen der Eckenlastschraube L im
Gegenuhrzeigersinn

verrückt die Differenz in die negative Richtung (+12 .. +11 .. +10 ..).
5. Die Differenz T
 R ist kleiner und negativ (-7d). Ein Schließen der Eckenlastschraube R im
Uhrzeigersinn

verrückt die Differenz in die positive Richtung (-7 .. -6 .. -5 ..).
6. Die Differenzen so lange gegen 0 stellen, bis alle vier Eckenlastwerte inner alb des tolerierten
Bereic s liegen. Um diese zu ermitteln, sie e Kapitel 3.2.1 ab Sc ritt 3.
L
TL
R
TR
T
L
R
T
T = tariert = 0