LOADING CELLS

BALL CLAY AND KAOLINS
PRE-PROCESSING LINE
USE AND MAINTENANCE HANDBOOK
LOADING CELLS
Customer: CHINA II PROJECT – ZIBO CHINA
Order: 2808
Year: CE 2010
CELLE DI CARICO A COMPRESSIONE - BASSO PROFILO
COMPRESSION LOAD CELLS - LOW PROFILE
CBL
* CBL
kg 250, 500, 1000, 2500, 5000, 7500, 10000 . . . . . . . . . . . . . . . . . . . . . . . . . .
CBL kg 15000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CBL kg 30000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CBL kg 50000, 100000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
* Versione cavo 10 metri / On request cable 10 m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Approvazione ATEX
II 1 G
II 2 D (zone 0-1-2-21-22) / ATEX approved (zone 0-1-2-21-22)
CERTIFICATO DI RIFERIBILITA’ SIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Opzione 2 ponti estensimetrici da 350 Ohm e 2 cavi di uscita (per sistemi a doppia sicurezza
ridondanti) / Option for dual safety redundant systems: two Wheatstone Bridges (350 Ohm) and two cables
A richiesta, per CBL da 2500 a 12500 kg, versione approvata
R60 C2 / C3 Vmin = Emax / 15000
On request, for CBL 2500 to 12500 kg, version approved
- ESECUZIONE ACCIAIO INOX 17-4 PH
- ERRORE COMBINATO < +/- 0,030 %
- GRADO DI PROTEZIONE IP 68
- STAINLESS STEEL 17-4PH CONSTRUCTION
- COMBINED ERROR < +/- 0.030 %
- PROTECTION RATING IP 68
øD
250
..
10000 15000
E
C
B
1/4 gas
øA
F
CAVO
CABLE
LUNGHEZZA :
CBL 250 - 10000
CBL 15000 - 100000
5 m
10 m
LENGTH :
CBL 250-10000
CBL 15000-100000
DIAMETRO
FILI CONDUTTORI
5 mm
4 x 0.25 mm 2
*
*
DIAMETER
CORES
A
82
100
126
165
B
44
48
54
80
C
32
35
40
60
D
22
28
35
60
E
14
14
14
26
F
15
15
15
15
Dimensions (mm)
CARATTERISTICHE TECNICHE
SENSIBILITA'
EFFETTO DELLA TEMPERATURA SULLO ZERO
EFFETTO DELLA TEMPERATURA SUL FONDO SCALA
COMPENSAZIONE TERMICA
CAMPO DI TEMPERATURA DI LAVORO
CREEP A CARICO NOMINALE DOPO 4 ORE
TENSIONE DI ALIMENTAZIONE MAX TOLLERATA
RESISTENZA D'INGRESSO
RESISTENZA DI USCITA
BILANCIAMENTO DI ZERO
RESISTENZA D'ISOLAMENTO
CARICO STATICO MASSIMO
CARICO DI ROTTURA in % sul FONDO SCALA
DEFLESSIONE A CARICO NOMINALE
50000
30000 100000
TECHNICAL FEATURES
2 mV/V +/- 0.1%
0.005 % / °C
0.003 % / °C
- 10°C / + 50°C
- 20°C / + 70°C
0.03 %
15 Volt
700 Ohm +/- 3
700 Ohm +/- 3
+/- 1 %
> 10000 MOhm
150 %
> 300 %
0.4 mm
SENSITIVITY
TEMPERATURE EFFECT ON ZERO
TEMPERATURE EFFECT ON SPAN
COMPENSATED TEMPERATURE RANGE
OPERATING TEMPERATURE RANGE
CREEP AT NOMINAL LOAD AFTER 4 HOURS
MAX SUPPLY VOLTAGE WITHOUT DAMAGE
INPUT RESISTANCE
OUTPUT RESISTANCE
ZERO BALANCE
INSULATION RESISTANCE
MAXIMUM STATIC LOAD
DESTRUCTIVE LOAD IN % ON FULL SCALE
DEFLECTION AT NOMINLA LOAD
SCHERMO
+ SEGNALE ( VERDE )
+ ALIMENTAZIONE ( ROSSO )
- SEGNALE ( BIANCO )
- ALIMENTAZIONE ( NERO)
SHIELD
+ SIGNAL (GREEN)
+ EXCITATION (RED)
- SIGNAL (WHITE)
- EXCITATION (BLACK)
Accessori di montaggio a pag. 50, 51, 52, 53 / Mounting accessories see pages 50, 51, 52, 53
48
ACCESSORI PER CELLE CBX 15000 - CBL 250-10000
P10000
MOUNTING KIT FOR LOAD CELLS CBX 15000 - CBL 250-10000
P10000 . . . . . . . . . . . . Piastra inferiore / Lower plate . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BASESUP . . . . . . . . . . . Base superiore tornita / Turned upper base . . . . . . . . . . . . . . . . . .
BASEINF . . . . . . . . . . . Base inferiore tornita / Turned lower base . . . . . . . . . . . . . . . . . . .
PIASTRA+BASE . . . . Piastra + base inferiore tornita / Turned lower base + lower plate
Bases and plates are constructed of AISI 304 stainless steel.
By means of a copper wire, connect the upper supporting plate
with the lower supporting plate, then connect all the lower
plates to the earthing system.
Gli accessori di montaggio hanno lo scopo di permettere il
corretto posizionamento delle celle di carico per ottenere la
massima affidabilità e precisione. Sarà compito del
progettista dell'impianto prevedere gli accorgimenti necessari contro gli spostamenti laterali e l’antiribaltamento in
funzione di: - Urti e vibrazioni; - Spinta del vento; - Classificazione sismica dell'area d'installazione; - Consistenza della
base di appoggio.
The use of weigh modules is strongly recommended to
simplify the installation of load cells and especially to
achieve optimal accuracy and reliability. To ensure the
stability of the structure the designer must consider further
contrivances according to the following conditions: - Knocks
and vibrations; - Seismic conditions; - Hardness of support
structure; - Wind effect.
25
Basi e piastre realizzate in acciaio INOX AISI 304.
Prevedere un collegamento mediante conduttore di rame tra la
piastra superiore e la piastra inferiore, poi collegare tra loro le
piastre inferiori alla rete di terra.
17,5
4 fori Ø15
PIASTRA + BASE
4 fori Ø14
150
115
150
17,5
115
150
25
150
200
BASESUP
50
22
18
22
M8x1.25
22
load cell
2
18
cella di carico
BASESUP
82,5
81
22
BASEINF
5
90
BASEINF
24
BASESUP
cella di carico
71
load cell
68
cella di carico
load cell
10
PIASTRA + BASE
4
200
P 10.000
P 10.000
bulloncini di fermo cella
50
ACCESSORI DI MONTAGGIO PER CELLE CBL - CBX
V10000
MOUNTING ACCESSORIES FOR LOAD CELLS SERIES CBL - CBX
V 10000 ( CBL kg 250 - 10000 ; CBX kg 15000 ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
V 10275 ( CBL kg 250 - 10000 ; CBX kg 15000 ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
V10000 weigh module is constructed of AISI 304 stainless
steel designed for silos, tanks, mixing machines, hoppers
subject to vibrations because of parts in motion. For a correct
installation is strongly recommended to utilize only the
accessory without load cell. Finished the installation
(weldings,etc..) by means of a copper wire, connect the upper
supporting plate with the lower supporting plate, then connect
all the lower plates to the earthing system; then proceed to
the load cell installation. Loosen the nuts (3), verify that
the bolts (2) do not touch the sides of hole of the upper late,
turn the nuts (4) without cause a weight increase, then fix
the load cells by using the bolts.
(1) Laminas against lateral forces
(2) Anti-tilt bolts to be used as jacks
(3) Nut to be used as jack
(4) Anti-tilt self-locking nut
Lower Plate must lay on supporting surfaces not
deformable.
The use of weigh modules is recommended to simplify
the installation of cells and especially to achieve optimal
accuracy and reliability. To ensure the stability of the
structure, the designer must consider further contrivances
according to the following conditions: Knocks and
vibrations; Seismic conditions; Hardness of support
structure; Wind effect.
10
Accessorio realizzato in acciaio INOX AISI 304 progettato per
la pesatura di sili, serbatoi, miscelatori, tramogge, soggetti a vibrazioni per organi in movimento. E’ buona norma procedere all’installazione del sistema pesato utilizzando solamente l’accessorio senza la
cella. Terminato il montaggio (saldature, ecc..) prevedere un collegamento mediante conduttore di rame tra la piastra superiore e la piastra
inferiore, poi collegare tra loro le piastre inferiori alla rete di terra; procedere all’inserimento della cella , poi allentare i dadi usati come martinetto (3). Verificare che il bullone (2) non tocchi a lato del foro della staffa
della piastra superiore e avvicinare i dadi antiribaltamento (4) alla distanza di circa 1 mm dalla piastra; infine rimontare i tre bulloncini di
fermo cella.
(1) Lamine contro lo spostamento laterale
(2) Bulloni con funzione di antiribaltamento e martinetto
(3) Dado da usare come martinetto
(4) Dado antiribaltamento autobloccante
La piastra inferiore deve appoggiare su superfici indeformabili.
Gli accessori hanno lo scopo di permettere il corretto posizionamento delle celle per ottenere la massima affidabilità e precisione. Sarà compito del progettista dell'impianto prevedere gli
accorgimenti necessari contro gli spostamenti laterali e
l’antiribaltamento in funzione di: Urti e vibrazioni; Spinta del
vento; Classificazione sismica dell’area d'installazione; Consistenza base di appoggio.
4
95
1
3
16MA
10
2
175
17,5
4 fori Ø14
LOWER PLATE
115
PIASTRA INFERIORE INOX
UPPER PLATE
150
PIASTRA SUPERIORE INOX
17,5
115
17,5
4 fori M12 x 1.75
17,5
150
150
30
115
175
30
30
115
175
30
PIASTRA INFERIORE INOX per mod. V10275
LOWER PLATE for mod. V10275
115
150
4 fori Ø14
PESO V10000 = 6 Kg
PESO V10275 = 7 Kg
(accessory’s weight)
17.5
240
275
51
17.5
Installation user’s manual
version 1.2
JOLLYTPS
WEIGHT TRANSMITTER
CALIBRATION AND ANALOG OUTPUT
SELECTABLE BY THE INSTALLER
2004/108/EC (EMC)
LEGENDA
Below are shown the simbologies used in the manual in order to warn the reader:
Caution ! High Voltage !
Caution ! This operation must be executed by skilled workers.
Read carefully the following indications.
Further information.
_________________________________________________________________________
TO BE FILLED OUT BY THE INSTALLER:
4-20mA
0-20mA
0-10V
CALIBRATION _____________________________________
Disposal of Waste Equipment by Users in Private Household in the European Union
This symbol on the product or on its packaging indicates that this product must not be disposed of with your other
household waste. Instead, it is your responsibility to dispose of your waste equipment by handing it over
to a designated collection point for the recycling of waste electrical and electronic equipment. The
separate collection and recycling of your waste equipment at this time of disposal will help to conserve
natural resources and ensure that it is recycled in a manner that protects human health and the
environment. For more information about where you can drop off your waste equipment for recycling,
please contact your local city office, your household waste disposal service or the reseller.
TABLE OF CONTENTS
RECOMMENDATIONS FOR THE CORRECT INSTALLATION ................................................. 1 – 2
TECHNICAL FEATURES................................................................................................................... 3
ELECTRICAL CONNECTIONS.......................................................................................................... 4
ANALOG OUTPUT MODIFY.............................................................................................................. 5
PUTTING INTO OPERATIONS.......................................................................................................... 6
TARE ZERO-SETTING ...................................................................................................................... 6
WEIGHT OSCILLATIONS.................................................................................................................. 6
CALIBRATION ............................................................................................................................ 7 - 8
CALIBRATION CHECK ..................................................................................................................... 9
MECHANICAL INSTALLATION CHECK........................................................................................... 9
LOAD CELLS VERIFY ..................................................................................................................... 10
RECOMMENDATIONS FOR CORRECT INSTALLATION OF THE LOAD CELLS
INSTALLING LOAD CELLS : The load cells must be placed on rigid and stable structures; it is
important to use the weigh modules for load cells to compensate for misalignment of the support
plates.
PROTECTION OF THE CABLE OF THE CELLS: Use water-proof sheathes and joints in order to
protect the cables of the cells.
MECHANICAL RESTRAINTS (pipes, etc.) : We recommend the use of flexible pipes and elastic
joints; in case of rigid pipes, place the end of the pipe as far as possible to the supporting structure
(at least 40 times the diameter of the pipe).
LOAD CELLS IN PARALLEL : Carry out the parallel connection of the cells by using a water-proof
junction box with terminal box. The junction boxes are provided with up to 8 cable glands plus one
cable gland for cable exit. The extension cables, connected to the load cells, must be shielded, led
alone into the piping or trough and laid as far as possible from the power cables (in case of 4-wire
connection: cable 4 x 1 mmq minimum section).
WELDING : Avoid welding while the load cells are installed.
WIND - KNOCKS - VIBRATIONS : The use of weigh modules is strongly recommended to
compensate for misalignment of the support plates and especially to achieve optimal accuracy and
reliability. To ensure the stability of the structure the designer must consider further contrivances
according to the following conditions: Knocks and vibrations; Seismic conditions; Hardness of
support structure; Wind effect.
EARTHING THE WEIGHING SYSTEM : By means of a copper wire, connect the upper supporting
plate with the lower supporting plate, then connect all the lower plates to the earthing system.
Electrostatic charges accumulated by the rubbing of the product against the pipes and the walls of
the container weighed are discharged to the ground without damaging the load cells. Failure to carry
out a proper earthing system, could not compromise the operation of the weighing system, but does
not exclude the future possibility of damages to load cells and instruments connected to them.
-1-
FAILURE TO FOLLOW THE RECOMMENDATIONS FOR INSTALLATION IS TO BE
CONSIDERED MISUSE OF GOODS.
OK
OK
NO
NO
NO
OK
RECOMMENDATIONS FOR CORRECT INSTALLATION OF WEIGHING INSTRUMENTS
The entry into the cable board of cells must be independent ( on one side or the other of the board )
and directly connected to the terminal board of the device without breaking by bearing terminal
boards or passing through troughs containing other cables.
Use the “ RC “ filters on the instrument-driven coils of the remote control switches.
Avoid inverter, if inevitable, use filters and separate with sheets.
In case of 230Vac supply, use a 380/230Vac transformer avoiding to use the 380Vac phase and the
neutral.
The installer of the board is responsible for securing the electrical safety of the indicators.
It is a good norm to let the indicators always switch on to prevent the formation of condensation.
-2-
MAIN FEATURES
DIMENSIONS: base 123 mm , depth 90 mm , high 65 mm.
HOUSING : resin container designed for mounting on Omega type brackets or DIN rails.
ASSEMBLY : panel rear or in compartment inside sealed enclosure.
EMPLOY: Normally used with max 16 bit analog / digital boards installed on programmable logic
(PLC)
TECHNICAL FEATURES:
POWER SUPPLY 24 Vdc +/- 15%
LINEARITY 0,01 % F.S.
THERMAL DRIFT 0,005 % F.S. / °C
POWER CONSUMPTION 6 W
MEASURING RANGE from 3 to 24 mV
ANALOG FILTER (10 – 90%) 100 – 1000 msec
CAPACITY max 6 load cells in parallel 350 Ohm
LOAD CELL CONNECTION 4-wires technique
LOAD CELL SUPPLY 10 Vdc / 180 mA
HUMIDITY (condensate free) 85 %
OPERATING TEMPERATURE - 10 to + 50 °C
STORAGE TEMPERATURE - 20 to + 70 °C
COARSE ZERO by 4 dip-switches ; from 0 to 17 mV
FINE ZERO by trimmer, 10% range
COARSE FULL SCALE by 4 dip-switches ; from 3 to 24 mV (1/6 F.S.)
FINE FULL SCALE by trimmer, 10% range
ANALOG OUTPUT :
Current output 4 - 20 mA dc max 400 Ohm
Current output 0 - 20 mA dc max 400 Ohm
Voltage output 0 – 10 Vdc min. 2000 Ohm
THE TRASMITTER IS PROVIDED WITH 4-20mA ANALOG OUTPUT (20mV=20mA).
TO MODIFY THE OUTPUT FOLLOW THE PROCEDURES AT PAGE 3; THEN PROCEED
TO THE CALIBRATION WITH SAMPLE WEIGHT OR BY MEANS SIMULATOR (SEE
PAGES 5 – 6 ).
-3-
ELECTRICAL CONNECTIONS
WARNING: The procedures here below described have to be carried out by
specialized personnel only.
-4-
ANALOG OUTPUT MODIFY
-
Remove the jumper E1 to obtain an analog output of 0 - 10 Vdc ( output on terminals 22 - 23 ).
-
Remove the jumper E1 to obtain an analog output of 0 - 20 mA ( output on terminals 21 - 23 ).
-
Close the jumper E1 to obtain an analog output of 4 - 20 mA ( output on terminals 21 - 23 ).
-
To increase the tare suppression over 17mV put a resistance of 10K instead of R5 (normally is
22 k).
-
To obtain an analog output with 30mV in input put a resistance of 8K instead of R33 (normally
is 4 K).
-5-
PUTTING INTO OPERATIONS :
Supply the transmitter and wait for about 10 minutes so that all components reach a steady
temperature. Make sure that the container is empty and without mechanical constraints.
By using a tester make sure that the output is positive and it increases if you subject the container to
a force weight, in case the output is negative check for the load cells connection and the correct load
cells installation ( direction of charge ).
TARE ZERO-SETTING:
Make sure that the container is empty and set the tare to zero as follows:
Use the zero fine trimmer for little variations, if it isn't sufficient use the dip-switches of coarse zero to
approach zero display as much as possible, then use the trimmer of fine zero again.
DIP-SWITCHES OF COARSE ZERO
0 = OFF 1 = ON
DIP-SWITCHES
POSITION
from - mV
to - mV
1 2 3 4
----
----
0 0 0 0
1 0 0 0
0 1 0 0
- 0,8
1,2
3,0
4,6
5,9
7,2
8,3
9,3
10,2
11,0
1,6
3,7
5,5
7,1
8,4
9,7
10,8
11,8
12,8
13,6
14,3
15,0
15,7
16,2
16,8
17,3
1
0
1
0
1
0
1
0
1
0
1
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
0
1
1
1
1
1
1
1
1
input mV to set to zero
11,8
12,5
13,1
13,7
14,3
14,8
WEIGHT OSCILLATIONS:
If the displayed weight is not steady it is possible to use an analogic filter ( a one-turn trimmer). Turn
the trimmer clockwise in order to reduce the oscillations. To inactivate the filter remove the E2
jumper.
-6-
The trasmitter is supplied pre-calibrated with 20mV = 4-20mA.
Proceed to a new CALIBRATION with sample weight or by means simulator.
CALIBRATION WITH SAMPLE WEIGHT
Make sure that the container is empty, verify that the output is 0Vdc or 0mA or 4 mA ( in accordance
with output used ), then put a sample weight equal to at least 50% of the full scale and use the
trimmer of fine full scale to move the corresponding output to the exact value, if the trimmer isn't
sufficient use the dip-switches of coarse full scale. Then check the 0Vdc or 0mA or 4mA again, and
if necessary adjust it again; put the sample weight and check the output, repeat this operation until
the output is corrected.
DIP-SWITCHES OF COARSE FULL SCALE
to obtain 20 mA or 10 Vdc output corresponding to the input mV
0 = OFF
DIP-SWITCHES
POSITION
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
2
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
3
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
4
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
1 = ON
input mV to obtain 10Vdc or 20mA output
from - mV
to - mV
---24
16,5
12,2
9,7
8,2
7,0
6,1
5,4
4,9
4,4
4,0
3,7
3,5
3,2
3,1
---15,2
11,6
9,3
7,8
6,8
5,9
5,3
4,8
4,3
4,0
3,7
3,4
3,2
3,1
2.9
-7-
CALIBRATION BY MEANS SIMULATOR
Use a cell simulator and a tester with scale in mV and at least a number after the comma.
Connect the simulator to the TPS.
Measure the mV in input on the terminals 4 ( + ) and 3 ( - ) and verify 0 mV; verify that the mA or
Vdc output is 0-4 mA or 0 Vdc ( in accordance with the model used ) otherwise use the dip-switches
of coarse zero and the trimmer of fine zero to move the output to those values ( usually the dipswitch 1 is in position ON ).
Measure the supply ( about 10V +/- 3% ) on the terminals 1 ( - ) and 2 ( + ).
Multiply this value by the rated output of the cells ( mV/V ) to obtain the mV value in input, rotate the
simulator to obtain this value on the terminals 4 ( + ) and 3 ( - ).
Use the dip-switches and the trimmer of fine full scale to obtain in output 20 mA or 5 - 10 Vdc.
Bring the mV input to zero and check the 4 - 0 mA or 0 Vdc output, otherwise adjust the new value.
Move the mV input to the full scale ( load cells supply x rated output ) and make sure that the output
signal is 20 mA or 10 Vdc.
Adjust the full scale if necessary.
If you want the signal 20mA or 10Vdc not at the cells full scale but at a middle value corresponding
to the net weight, use the following equation to calculate the input value in mV :
mVtot : F.S. cells = mVS : S
mVtot = Millivolt corresponding to load cells supply x rated output
F.S. cells = Full Scale ( number of load cells x rated load )
mVS = Millivolt input
S
= weight for the one you want the 10Vdc or 20mA output
Example:
load cells supply = 9,99 ;
rated output = 2mV/V ;
n° cells = 4 ;
rated load = 2500 kg ;
weight for the one you want the 10 Vdc or 20 mA output = 4000 kg
mVtot : F.S. = mVS : S
( 9,99 x 2 ) : ( 2500 x 4 ) = x : 4000
19,98 : 10000 = x : 4000
x = ( 19,98 x 4000 ) : 10000 = 7,992mV
so with a input signal of 7,99 mV the output signal obtained must be 10 Vdc or 20 mA.
-8-
CALIBRATION CHECK:
If you want to check the calibration, after the tare zero-setting, put a sample weight equal to at least
50% of the max load capacity on the load system and check the value of the output signal; if the
output is different from the sample weight verify that the weight difference does not depend from
some mechanical cause, eventually move to the Mechanical Installation Check.
MECHANICAL INSTALLATION CHECK :
With a tester measure the load cells supply on the terminals 1 and 2 and make sure that there is a
supply of about 10 Vdc).
When the container is empty measure the signal in mV on the terminals 3 and 4.
Put a sample weight on the scale and measure the signal in mV again.
Make sure that the signal increase corresponds to the result of the following equation:
mVtot : F.S. cells = mVS : S
mVtot = Millivolt corresponding to load cells supply x rated output
F.S. load cells = Full Scale ( number of load cells x rated load )
mVS = Millivolt increases because of sample weight
S
= sample weight
Example:
n° load cells = 3 ;
rated load = 1500 kg ;
rated output = 2mV / V ;
load cells supply = 9,98 Vdc;
sample weight = 1000 kg ;
mVtot : F.S. cells = mVS : S
( 9,98 x 2 ) : ( 1500 x 3 ) = x : 1000
19,96 : 4500 = x : 1000
x = ( 1000 x 19,96 ) : 4500 = 4,435
so with a sample weight of 1000Kg on full scale of 4500 Kg, the increment will be: 4,435 mV.
- If the value in mV is correct and the output signal is wrong, probably non-authorised operators
have changed the full scale by mistake, therefore move on to the Calibration page.
- If the value in mV is lower than the calculated value, probably there are mechanical friction, after
verifying them move on to the Load cells check.
- If the value in mV is superior to the calculated value move on to the Load cells check.
-9-
LOAD CELLS VERIFY
Load cells resistance measure:
Use a digital tester.
- Disconnect the load cells from the instrument ( or amplifier ), make sure that there is not any
moistness caused by condensed water or infiltration of water. If so, keep cleaning the system or
replace it, if necessary.
- Carry out the measurment of the resistance as follows:
- The value between the positive signal wire and the negative signal must be equal or similar to the
one indicated in the load cell data sheet (Output resistance).
- The value between the positive supply wire and the negative supply must be equal or similar to
the one indicated in the load cell data sheet (Input resistance).
- The insulation value between the shield and any other wires and the body of the load cell must be
higher than 20 MOhm (mega Ohm).
Load cells tension measure:
Use a digital tester.
- Take off the load cell you intend to check from underneath the container.
- Make sure that the supply of the load cell connected to the instrument ( or amplifier ) is 5 Vdc +/3 % (10 Vdc +/-3% for instrumets series TPS and TPZ).
- Measure the signal between the positive and the negative signal wires directly connected to the
tester, make sure that there is a signal included between 0 and 0,5mV ( thousandth of a Volt ).
- Load the cell and make sure that there is an increasing of the signal.
IN CASE ONE OF THE ABOVE CONDITIONS IS NOT MET, PLEASE CALL THE
TECHNICAL ASSISTANCE SERVICE.
- 10 -