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The RCS-6V kit Page of Contents Page

1. This Book 1.1. Warning & safety 3

1.2. What can I do with the RCS-kit? 3 1.3. Tips 3

2. The principle of the system 2.1. How the load measurement system works 5 2.2. The reference height 6

3. Mounting the RCS-kit 3.1. Part in the kit 7

3.2. Mounting the sensor 8 3.3. Mounting the indicator 9 3.4. Mounting the cable 9

3.5. Placing the stickers 10 3.6. The machine sticker 10 3.7. Placing the batteries 10

3.8. Power supply by truck battery (option) 11 4. Setting the capacity and the graduation

4.1. Determining the capacity of the truck 11 4.2. Setting the graduation 12

5. Calibration 5.1 Attention! Before you begin calibration 13 5.2 Zero point adjustment 13

5.3. Calibration 13 6. Taking the system into use

6.1 Turning the system on and off 14 6.2 Using the reference height 15 6.3. How can I weigh as accurately as possible? 15

6.4. The indicator 16 6.5. The touch panel 17

7. The functions of the load measurement system 7.1. Zero point correction 17 7.2. Gross weighing 18

7.3. Net weighing: automatic tare 18 7.4. Net weighing: manual tare entry 18 7.5. Totalling 19

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8. Changing the calibration time for more accurate weighing 20

9. Specifications and options 9.1. Specifications 20 9.2. Options 21

10. Most frequently occurring problems 10.1 The display does not freeze the weight value, but stays unstable 21

10.2 The display freezes or gives an incorrect weight 21 10.3. Inaccurate weights are shown after installation or first use 22 10.4. Weighing errors on systems which are already in use 23

Rev.30.11.09

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IP65

1. THIS BOOK

This book explains how the hydraulic measuring system can be used and how the parts in the kit are mounted.

1.1. Warning & safety measures

When using the RCS please observe carefully the instructions and guidelines contained in this manual. Always perform each step in sequence. If any of the instructions are not clear, please contact RAVAS.

- All safety regulations that apply on the truck remain valid and unchanged - RAVAS is not responsible for any physical harm done to the operator because

of the presence of the indicator in the cabin. - Any modifications done to the system must be approved in writing from the

supplier, prior to any work being completed.

- It is the sole responsibility of the purchaser to train their own employees in the proper use and maintenance of this equipment.

- Do not operate this unit unless you have been fully trained of its capabilities.

- Check the accuracy of the scale on a regular basis to prevent faulty readings. - Only trained and authorized personnel are allowed to service the scale. - Always follow the operating, maintenance and repair instructions of this truck

and ask the supplier when in doubt. - RAVAS is not responsible for errors that occur due to incorrect weighings or

inaccurate scales.

- No weighing operations are allowed if any persons or objects are in the vicinity; around, under or close to the load.

1.2. What can I do with the RCS-kit?

The RCS is a hydraulic measuring system for forklift trucks and stackers. By measuring the oil pressure in the lifting cylinder an indication is given of the weight lifted. Measuring the oil pressure is very precise but mechanical parts in the lifting

mechanism and, for example, the position of the mast can restrict the accuracy.

1.3. A few tips It is possible to increase the accuracy. Here are a few tips on own to ensure that the

systems weighs as precisely as possible.

min -10°C15°F

0 0

max 40°C105°F

4

Keep the mast vertical while weighing (an angle of 2 to 3 degrees has almost

no affect);

Put the centre of gravity of the load in the middle of the forks;

Weigh at a set height;

Do not take the forks to the reference height (the height at which the stickers

on the carriage plate and mast are opposite each other) too fast. It is best to take the forks above the reference height and then lower them to the reference height. Do this slowly, without a sudden stop;

When the reference height is reached the weight is frozen in the display. The display will not freeze for loads underneath 20 graduations; on a system with a graduation of 5kg, for example, this is 100kg;

Make sure that the system is first unloaded, before a new weighing is begun.

Chapter 6.2. describes in more detail how to ensure that the load measurement system is more accurate.

The hydraulic measuring system has a maximum tolerance of 2% of its capacity. At a capacity of 2500 kg, that is a difference of 50kg!

When used correctly, the accuracy is usually significantly higher.

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2. THE PRINCIPLE OF THE SYSTEM

2.1. How the RCS-system works

The load measurement system measures the oil pressure with an oil pressure sensor. The pressure in the lifting system depends on the load on the fork lift system.

Measuring the oil pressure is very precise but mechanical parts in the lifting mechanism and, for example, the position of the mast can restrict the accuracy.

The „slip and stick‟ effect causes less repeatablility, and thus less accuracy.

Repeatability means that when the same load is weighed several times, the same weight is shown in the display.

The friction/resistance of the rolls, with which the carriage plate moves in the mast, has a big influence on the

weighing. The resistance in the rolls, through dirt or bad bearings, increases the inaccuracy that is created by:

internal leaks in the oil circuit;

non-central loading of the forks

(the load is not in the middle of the forks);

the difference due to slow or fast

approach of the reference height.

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2.2. De reference height

The centre of gravity of the load has to be exactly in the middle of the forks. If the

centre of gravity is on the ends of the forks, or if one fork is loaded more than the other, then the friction in the mast is significantly higher and the measurement will be less accurate. Chapter 6.2. describes how to weigh with the most accuracy.

To reduce the influence of the condition of the mast and the cylinder, the weighing is always

performed at the same height. To ensure this, stickers are placed on the mast and carriage plate to clearly mark the reference height at which the

weighing should occur. First lift the forks past the reference point and then

lower the load to the point where the stickers are opposite each other. This results in the optimal accuracy.

For the best result from the system,

that is, for minimal influence from the friction and resistance in the mast, the weighing should take place with the

mast in the vertical position!* * An angle of 2 to 3 degrees has

almost no influence.

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3. MOUNTING THE RCS-KIT

3.1. The parts in the kit

Sensor Protective cover for the sensor cable

Indicator Stickers to mark the reference height

Penlight batteries Machine stickers model AA

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3.2. Mounting the sensor

Before you start:

Read chapter 2. The way the system works is described there. Understanding

how the system works will make mounting the components easier.

Ensure that there is no pressure on the high-pressure hose.

The sensor is mounted with a T-piece in the high-pressure hose, between the valves and the cylinder.

The connection on the sensor is G¼” BSP male.

Mount the T-piece so that the sensor and the cable connection are pointing

downwards. This will prevent air getting into the sensor.

Protect the cable against moving, sharp or warm parts with the supplied

protective cover.

Choose a place to mount the sensor:

Mount the sensor in the pressure hose that steers the cylinder. The cylinder moves the carriage plate. Normally there is only one pressure hose.

Do not mount the sensor too close to the engine. Large differences in temperature can influence the accuracy of the system.

If the truck is used intensively, a piece of pipe or hose of ± 50 cm can be

mounted between the sensor and the T-piece. The sensor is sensitive to temperature differences. If the moving oil becomes warm, the standing oil in

this pipe or hose will remain cool. The sensor will not be effected by temperature differences.

Place the sensor close to the cylinder. There is often more room there and it is

easier to reach.

Choose, if possible, a place to mount the sensor where there are the least few

steering and safety valves between the sensor and the cylinder.

1. Sensor

2. Sensor cable with

connector

3. Sealing ring

4. T-piece (not supplied with the kit)

The sensor has to be mounted, as shown, with the cable connector pointing downwards.

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3.3. Mounting the indicator

The indicator is supplied with a steel mounting bracket. This bracket can be used to hang the indicator up or mount it standing. Choose the correct place to mount the

indicator and make sure that:

the indicator is visible and within reach of the chauffeur;

the indicator is hung high enough so that the chauffeur does not hit his head;

the indicator does not restrict the movement of the steering handles;

there is still sufficient leg room;

the indicator does not restrict the access to the engine or the battery.

3.4. Mounting the sensor cable

When mounting the cable, it is important that the cable is kept tidy and protected. Keep the cable out of sight as much as possible to prevent the possibility of damage

to the cable. It may be necessary to thread the cable through small openings, through which the

18mm connector does not fit. In that case it is possible de dismount the cable and the connector from the indicator. The photo‟s show how that can be done.

The system is supplied with a protective cover for the cable. This can be used where:

the cable is near parts of the lift truck that become hot;

the cable is mounted near moving parts.

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3.5. Placing the stickers

Two stickers are supplied with this kit. The arrow stickers are used to show the reference height. One of the stickers is placed on the mast and one on the carriage plate. The photo shows where the reference height is on the truck.

Attention:

Make sure that the chauffeur can see

the stickers;

Make sure that there is a minimal

distance between the two arrows. The larger the distance, the more difficult it will be to gauge the height accurately;

Choose a practical height: not too high, because then lifting will take more

time. Moreover, it may be dangerous to lift heavy loads too high.

3.6. The machine sticker

As described in the CE directive for weighing systems, a machine sticker has to be applied to the weighing system. The sticker shows the capacity and

the graduation. The stickers that are supplied with the kit are suitable for different capacities. Apply the correct sticker as shown:

3.7. Placing the batteries

4 AA penlight batteries are needed, it does not matter which type. The batteries supplied are not rechargeable.

Loosen the screws at the front of the indicator.

Remove the front part of the indicator. Be careful for the cable connections! Make sure you do not pull at them.

Place the batteries. Be careful not to damage the system and place the batteries

correctly. Pay attention to the + and – signs. Screw the indicator closed again.

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+ - +

_Black

Red

Blue

Brown

EU US

3.8. Power supply by truck battery (option)

If the indicator is equipped with an integrated 12V power regulator, which can be verified by reading the label on the indicator housing, then the indicator must be connected directly to the truck battery. The 12V power regulator can be ordered as

an option.

4. SETTING THE CAPACITY AND GRADUATION

4.1. Determining the capacity of the truck

The graduation of the indicator depends on the capacity of the lift truck. The European directives for weighing systems state that the machine stickers should show the producer, the capacity and the graduation. The kit contains a number of stickers with different capacities and graduations.

For a capacity of 2500 kg the weight is shown in 5 kg steps;

For a capacity of 5000 kg the weight is shown in 10 kg steps;

For a capacity of 10000 kg the weight is shown in 20 kg steps.

!!! IMPORTANT!!!

If the lifting capacity of the forklift truck is different then the above-mentioned e.g. 1500 kg or 3000 kg, a higher capacity should be chosen. For 1500 kg the capacity will be 2500 kg; for 3000 kg it will be 5000 kg. If you choose a setting and machine

sticker with a smaller capacity, and therefore a smaller graduation, then the measurement range and accuracy will not be in accordance with the specifications.

The standard setting of the indicator is a capacity of 2500 kg and a graduation of 5 kg. The following procedure should be followed to change the settings.

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4.2. Changing graduation

To go to the parameter menu: Switch off the indicator. Press 23 seconds on the on/off key. (Don‟t let go!)

Wait till the indicator displays P01. Use parameter (P02) to enter the correct graduation:

Use the keys and to go to P02. Confirm with (0/T).

The indicator shows the graduation: 5 (5 kg).

Modifying the graduation:

Use the and to change the graduation to:

10 for systems with a capacity of 3000 kg to 5000 kg. 20 for systems with a capacity of more than 5000 kg.

Confirm with (0/T).

The indicator shows P03. Parameter (P05) to enter the correct weighing capacity:

Use the keys and and go to P05. Confirm with (0/T).

The indicator shows the capacity 02500 (2500 kg) of which the digit 5 is flashing.

Use the keys and and change this value to 0. Confirm with (0/T).

The indicator shows the capacity 02000 of which the digit 2 is flashing.

Use the keys and and change the value to:

3 for 3000 kg or 5 for 5000 kg or 0 for 10.000 kg

Confirm with (0/T).

The indicator shows the capacity 03000 of 05000 of 00000 where the 0 on the left is flashing.

When a capacity of 10.000 kg is needed, use the keys and and change this

value to 1. Confirm with (0/T).

The indicator shows P06.

To leave the parameter menu: Press 3 seconds on the key (0/T) to leave the parameter menu and return to

the load measurement mode.

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5. CALIBRATION

5.1. Attention! Before you start calibration:

The calibration of the system should take place at the reference height, as

described in chapter 2.2.

The mast needs to be vertical when calibrating and measuring loads.

When calibrating a calibration weight is needed of 50 to 75% of the capacity of the lift truck.

When calibrating at the client, weigh the pallet on another weighing system. That weight can be used as the calibration weight.

Make sure, when calibrating, that the centre of gravity is in the middle of the forks.

5.2. Zero point calibration

Make sure the system is unloaded and the mast is vertical. Switch the system on. Lift the system to past the reference height and lower it to the reference height. Push the (0/T) key for about 8 seconds.

The display counts down from AF 08 to AF 00. The indicator shows which percentage of the total capacity has been zeroed,

e.g. AP 6.4. This percentage should not be higher than 40. The zero point has been defined, the system automatically returns to standard

weighing mode.

Check if the zero point is stable. Lower the carriage plate to the reference height a few times and check whether the zero point (± one or two graduations) returns.

5.3. Calibration

Push the PT key for 18 seconds.

The display will go blank until calibration mode has been reached.

The indicator shows the value of the first calibration point, the lowest indication bar is flashing.

Load the load measurement system with a known weight. The cursor keys are

used to enter the weight on the forks into the system. Press the (0/T) key shortly.

The first segment starts flashing.

Use the and keys to change the segment. Confirm the value by pressing the (0/T) key.

The second segment starts flashing.

Use the and keys to change the segment. Press the (0/T) key.

Repeat this procedure until all the segments show the correct value for the

calibration weight. When each segment has been corrected, the lower indication bar will flash

again.

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If this is not the case, press the (0/T) key until the lower indication bar

starts flashing.

ATTENTION: the following two points need to be executed in quick succession. Lower the forks to reference height. Confirm the entered weight immediately by pressing the (0/T) key for 3

seconds. The display counts down from AF 08 to AF 00, the first calibration point has

been set. Leaving the calibration mode:

Leave calibration mode by pressing the or key until AP XX appears. This number indicates the calibration sensitivity percentage, e.g. AP 07.

Return to standard load measurement mode by pressing the (0/T) key until

the display goes blank. Turn off the load measurement system and turn it back on again.

Weigh the calibration weight a few times by lowering it to the reference height. The load measurement should be repeatable, within the tolerances of the system, which

is 2% of the capacity of the load measurement system. That means that, at a capacity of 2500 kg, the difference will not be more than 50 kg.

If the weight result is not repeatable, repeat the whole calibration procedure, paying attention to the following aspects: Do not vary the speed with which you approach the reference point;

The centre of gravity has to be in the middle of the forks; Make sure the mast is vertical.

If, after the two or three attempts, the weighings are not repeatable, refer to Chapter 8: „Optimal calibration‟ or Chapter 10: „Most frequently occurring problems‟. .

6. TAKING THE SYSTEM INTO USE

6.1. Turning the system on and off

The load measurement system is turned on with on and off key on the indicator. The system will turn off after 3 minutes. This saves the power of the battery. When the batteries are empty, LO-BA will flash in the screen of the indicator. It is still

possible to perform a number of weighings before the system turns off completely. Attention! It is only possible to press a key when the weight is stable in the display.

The “load stable” indication can be seen in the indicator display. If the load is not stable, the keys will not react. This prevents mistakes. Weighing or adding a moving load is not accurate.

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6.2. Using the reference height

Lift the forks a little bit higher than the point at which the stickers are on the carriage plate and lower them to the reference height. For more information on the reference height see chapter 2.2.

6.3. How can I weigh as accurately as possible?

As explained, the hydraulic measuring is very precise but the accuracy is influenced by the mechanical parts, for example, through dirt of bad bearings in the mast, or

internal leaks in the oil circuit. Or because the load to be weighed is not in the middle of the forks. Another cause is that the system is not used correctly.

It is possible to increase the accuracy. How?

By keeping the mast vertical during the load measurement. (An angle of 2 to 3

degrees has almost no influence);

By putting the centre of gravity in the middle of the forks;

By measuring the load at a fixed height;

By not taking the forks to the reference height to fast. It is best to lift the forks

past the reference height (the height of the stickers on the carriage plate and mast) and then lower them to the reference height. This should be done

slowly, without sudden stop;

When the reference height is reached the weight is fixed on the display. At this time the weights are added by the system;

The display will not freeze for loads underneath 20 graduations; on a system with a graduation of 5kg, for example, this is 100kg. These weighits will also

not be added to the total.

Make sure that the system is unloaded before a new weighing is started.

Calibrate the systems correctly. See chapter 5: Calibration.

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6.4. The indicator

Front indicator

Display indications

By means of three pointer bars the display of the indicator shows:

◄ The load measurement system (including load) is stable ▬ The weight shown is negative

NET ◄ The display shows the net weight

The following indications can be shown in the display: HELP 1 The load measurement system has been overloaded.

HELP 2 The zero point is below the originally calibrated zero point. See load

measurement system calibration.

HELP 3 Negative signal from the sensor.

HELP 4 The tare value entered (manually) is too high. Press key PT again to

delete this help message and key in a lower tare value.

HELP 7 Signal from the sensor is too high. LO-BA The batteries are (almost) empty.

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6.5. The touch panel

Each key has an operational and an entry function. Operational

function

Entry function

zero setting and

automatic tare

confirm and

digit to the left

tare entry

decreasing flashing digit

totalling

increasing flashing digit

on / off

!!! IMPORTANT!!! Operation of a key is not accepted unless the load measurement system is

stable (and the “load stable” sign lights up). This means that the indicator only executes commands with a stable load.

7. THE FUNCTIONS OF THE RCS-SYSTEM

7.1. Correct zero point

To check the zero point the forks have to be freestanding and they may not touch the ground. They should, of course, be empty.

Lower the forks to the reference height and check whether the display on the

indicator shows a zero. If not, press the 0/T key.

On many systems (dependant on the condition of the lift truck) the display will stay on 0 kg between the lowest position (forks not on the floor) and, for example, a height of

two meters. If this is the case, the forks do not have to be lowered to the reference height to check the zero point. This is also true when checking after a lifting or lowering movement. The zero point can be checked without further actions.

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7.2. Gross weighing

Before starting a new weighing, make sure that there is nothing on the forks. Check whether 0 kg is still shown on the display. See also the paragraph „correct zero point‟. Lift the load past the reference height. See also chapter 2.2. Then lower the forks

calmly to the point at which the reference height arrows are opposite each other. After a short time the display will show the „load stable‟ indication.

With a load on the forks, it is possible to check whether the height at which the weighings take place is of influence is on the weight shown. If it is clear that there is little difference, and the accuracy is not of high importance, then it is possible to

weigh at different heights, which can save time.

7.3. Net weighing: automatic tare The indicator offers the possibility to reset tare weights to zero automatically. This

way added or subtracted weights can be determined. ATTENTION: It is not possible to do dosing with this load indication system! It is not

possible to register the addition or subtraction of weight without returning to the reference height.

Lower the load to reference height.

Press the 0/T key.

The indicator is set to zero.

The "NET" pointer shows that a tare weight is activated.

Place or remove the net load.

The display shows the net value of the weighed load.

When removing load, this is a negative value.

By executing a zero setting in unloaded position, the system will return to the standard load measurement mode.

7.4. Net weighing: manual tare entry By pressing the PT key a tare can be entered. After a known tare weight, for

example the packaging, has been entered, the net weight is shown on the display. This happens as follows:

Make sure that the forks are unloaded (do not enter a tare value when the forks

are loaded: this will decrease the measurement precision).

Make sure the indicator indicates zero (correct the zero-setting if necessary by pushing the 0/T key).

Activate the last entered tare value: Press the PT key.

The display shows the current tare value.

The digit on the right flashes. Press ENTER () for three seconds if the current tare value is required.

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To enter a new tare value: Press the PT key.

The display shows the current tare value. The digit on the right flashes.

Press the key to go up a value or press the key to go down a value until the

required value is reached. Press ENTER () to change the next value.

Repeat this procedure until the required tare value is displayed. Press ENTER () until the last segment has stopped flashing.

The tare weight is activated.

The “NET” pointer lights up. When the system is loaded at this moment, the net value appears in the

display.

When the system is unloaded, the read-out displays the given tare value negatively.

7.5. Totalling

The indicator offers the possibility to add up weighings and show the total weight. When a tare weight is active, the net weight is added up automatically.

Adding new weights: Load the system.

When the weight is stable, press the Σ key to add the weighed load to the total

weight.

The value of the display is stored and added in the memory.

In turn, the indicator shows the sequence number (number of weighings) and

the (sub)total.

After a few seconds the system will automatically return to the standard load

measurement mode.

Check the total weight or print and reset: Press the Σ key for three seconds to refer to the total weight calculated thus far

(without totalling).

In turn, the indicator shows the sequence number (number of weighings) and

the (sub)total current in the memory.

After a few seconds the system will automatically return to the standard load measurement mode. You can now continue totalling.

The memory can be erased by pressing the Σ key during the display of the total.

If the system is equipped with a printer, an overview print is made.

The display shows sequence number 00 and the total weight 0 kg.

The system will automatically return to the standard load measurement mode.

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8. CHANGING THE CALCULATION TIME TO IMPROVE THE ACCURACY

When the load is lowered to the reference height the indicator software registers a peak and then a slow reduction in the oil pressure. During this period a number of

calculations are made, after which the weight is shown, fixed and stable, on the display. This calculation time can be set. The default time is 4 seconds. If this time is

increased the accuracy of the load measurement system is higher. The disadvantage, however, is that each load measurement takes more time. To change the calculation time, follow this procedure:

To go to the parameter menu: Switch off the indicator.

Press 23 seconds on the on/off key. (Don‟t let go!) Wait till: The indicator displays P01.

Use parameter P01 to set the required calculation time: Enter with (0/T).

The indicator shows: 04.

Use the and keys and change this value to a maximum of 9 (nine seconds) or choose a lower calculation time.

Enter with (0/T).

The indicator shows P02.

To leave the parameter menu: Press 3 seconds on the key (0/T) to leave the parameter menu and return to

the load measurement mode.

9. SPECIFICATIONS AND OPTIONS 9.1. Specifications

Maximum inaccuracy 2% of the capacity of the load measurement system (50 kg at a capacity of 2500 kg).

The pressure sensor is suitable for lift trucks with a system pressure of 600 Bar. Water and dust proof according to the IP65 norm. System power through 4 AA penlight batteries, 2500 Ah.

Autonomy is 450 hours, 2 years at 20 weighings per day.

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9.2. Options

Printer Roll printer for registration of exceptional weights and the total weight.

Fixed power supply Instead of the use of AA penlight batteries, the system can be

connected to the lift truck battery. These options cannot be added once the system is mounted and can only be bought

with a new system.

10. MOST FREQUENTLY OCCURING PROBLEMS

10.1. The display does not freeze the weight value, but stays unstable.

Cause When you lower the forks to the reference marks then the indicator will measure a small peak in the hydraulic pressure when stopping this lowering action. At this moment a calculation is started which results in the weight value

freezing in the display. When the reference height is approached too slowly then the indicator will not sense a pressure peak hence there will be no frozen weight reading in the display. The weight display will keep on counting down because of

the characteristics of the hydraulic components and also because of the „stick and slip effect‟ caused by the roller friction in the mast. Solution lift the forks above the reference level and lower with slightly more

speed to the reference height. The display will not freeze for loads underneath 20 graduations; on a system with a

graduation of 5kg, for example, this is 100kg.

10.2. The display is locked up or gives totally wrong values Cause could be: a new calibration has been executed without deleting the old

calibration values – these need to be reset to zero before starting a new calibration. Without this multiple calibrations point will stay active. These points can be set to zero as listed below:

Go to the calibration menu Press the PT key for about 18 seconds (this may be 8 seconds on older

versions). The display will go blank until calibration mode has been reached. The indicator shows the value of the first calibration point, the lowest

indication bar is flashing.

Check whether the old calibration points are still active. If they are, set them to

zero.

Press the key. The middle bar is flashing; the second calibration point is displayed.

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Use the and keys to change all segments, confirming the value per segment by pressing the (0/T) key, until each segment is set to zero.

Press the key. The highest bar is flashing; the third calibration point is displayed.

Use the and keys to change all segments, confirming the value per segment by pressing the (0/T) key, until each segment is set to zero.

Press the key twice to return to the first calibration point.

The lowest indication bar is flashing.

10.3. Incorrect weights are shown after installation or first use

The system only works properly when the zero-point is stable and remains stable. When errors remain, despite a stable zero point, check the following

points:

Place a large load (¾ off the truck capacity) on the forks and weigh the load by

lowering it to the reference height. Repeat that and check if the weight readings are repeatable – NB errors until 2% are possible.

If the repeatability test is positive, testing with one test load gives an accurate and consistent result, then you can proceed to test with multiple loads to check if the system is linear.

Weigh 3 different loads i.e. +/- 500, 1000 en 2000 kg using another (accurate)

weighing system and then use the load measurement system. (Also check if the different weights are repeatable).

When all weights have the same percentage of error then the system has to be

calibrated (again).

When one of three loads is correct and one of the two others has an error of more

than 2% only then it makes sense to execute a multiple point calibration, see also Chapter 8.

The system shows irregular values:

Cause High friction in the cylinder, mast, guiding strips or chain rollers. Solution Look where the friction is coming from and solve the problem.

(Contact your forklift truck dealer).

Cause Safety valves or valves, which control the lift and lowering sequence of

the multiple cylinders, can be of influence on the pressure in the system. Solution Check if the error occurs after a certain action. For instance when

the second or third mast is active, or certain valves are active. Taking all loads

off the forks by resting the forks on the floor can cure the problem and it will also activate a new weighing. Check whether relocating the sensor could be a solution to the problem.

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10.4. Weighing errors on systems which are already in use

First check whether the errors are caused by incorrect use of the load measurement system, by following the instructions below. If the problems are not solved refer to Chapter 10.3. Incorrect weights are shown after installation or first use.

The error is consistent:

Solution Check if the zero point is stable.

Lift the forks with no load on just off the ground, set the display to 0 kg and move

the forks a bit to check if the display stays on 0 kg. Small changes of 5 or 10 kg (one or two increments) are possible.

Errors only occur at certain moments during the day:

Cause Temperature differences. The hydraulic oil is heating up the sensor. The

hydraulic oil now has less friction in the cylinders etc. Solution Mount the sensor using a piece of hose or pipe, a bit further away

from the T piece and also away from the pump and/or the hydraulic circuit. The oil in the little hose or pipe is not flowing and will react as a temperature isolator so that the sensor will no longer heat up.

Normally speaking, the change in friction cannot create errors greater then 2% of the scale capacity. The errors should stay within the specification of this hydraulic

load measurement system.

The error only occurs with certain operators of the system:

Cause Operators use the system in their own way. Solution Train all operators to use the system in the same way. Then the

system has to be calibrated in accordance with the way the system is used. The operators can choose if they lower the forks to the reference point quickly or slowly and then the calibration has to be done in the same way. If other

methods are used than described in this manual, then the results can fall outside the accuracy specifications.