Minimize Weighing Riskby Adopting Good Weighing Practice™

Guaranteed Quality

Minimized Risk

Reduced Costs

Secure Audits

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GWP®

Good Weighing Practice™

2 METTLER TOLEDO Hazardous Area

Regulatory compliance & increased productivity& the principles of Good Weighing Practice™

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The weighing experts of METTLER TOLEDO help you understand ■ which factors affect the reading and the performance of a weighing device and the quality of your products.■ how the selection of the right scale is critical for meeting your manufacturing requirements and assuring the quality of your products.■ the regulations that govern weighing so that your weighing processes are in full compliance all the time.

The GWP® processGood Weighing Practice™ is aguideline that allows you to improveyour whole measuring process.It is based on a defined set of acti-vities and culminates in the produc-tion of documentation that can beused to justify the steps taken to anexternal or internal auditor.

An optimal level of activity leads youto compliance. Not more, not less!Don’t compromise between:■ Managing your risks■ Managing your quality■ Managing your productivity

We can help you find the right balance.

Example: GMP 21 CFR part 211

Subpart D-Equipment

§ 211.68 Automatic, mechanical, and elec-tronic equipment.

“Automatic, mechanical or electronicequipment […] shall be routinely calibrated, inspected or checked according to a written program designed to assure proper perfor-mance. Written records of those inspections shall be maintained.”

GWP®: at the heart ofregulatory compliance

The five step GWP® process

Routineoperation

Evaluation

Selection

Installation

Calibration

Whatever the industry, regulatory compliance is an essential part of modern manufacturing. Regulations cover almost every aspect of the manufacturing process and a failure to meet these regulations can be expensive both financially and in reputation.

www.mt.com/gwp

How dowe (I) putthis intopractice?

3METTLER TOLEDO Good Weighing Practice™

Manufacturing and regulatory compliance:Each manufacturing process operates to different parameters to ensure optimal product quality:■ Process tolerances■ Weighing range and Minimum Weight■ Operational risks■ Applicable standards (GMP, ISO, IFS, BRC, HACCP, etc.)

Understanding your processUsing metrology and operating procedures to mitigate risks

Evaluating your needs means understanding the regulations governing your industry but also asking the right questions about your process.

Metrology and operating proce-dures impact your quality.In the past, the interpretation of the regulations and the selection of a weighing device have not always been considered together. Experi-ence proves that it is not only the

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weighing instrument, but also its environment and the way it is used that impacts directly on quality.GWP® addresses the needs of all current Quality Management Sys-tems such as ISO, IFS, BRC, GMP and HACCP, it relates them to your

weighing process and puts them into meaningful practice for your specific application.

GWP® helps you ask the right questions to meet all quality rele-vant standards.

Evaluation

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Fact based selection of the weighing systemEnsures compliance and productivity

It is often the smallest component in a recipe that has the greatest impact on the final product. This is why the Measurement Uncertainty and theMinimum Weight play a critical role in correct scale selection.

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User Question: So how do I select the correct scale to meet my manufacturing tolerance of ±1%?

Answer: Select the scale with the appropriate Minimum Weight.

Minimum WeightThe Minimum Weight is the weight at which the relative measurement uncertainty becomes higher than the tolerance required by the process (e.g. ±1%). Any measurement above this limit would not comply with the required manufacturing tolerance.

GWP® and scale selectionDuring the Evaluation Step you deter-mine the smallest net weight of your process. During the Selection Step only the scales that meet both your manufacturing requirements and have an appropriate Minimum Weight will be recommended.

The MinWeigh functionOnce determined during calibration, the Minimum Weight of the scale is stored on the terminal. Then an icon will appear on the display if the operator tries to weigh below the Minimum Weight.

For more information on Minimum Weight, download our dedicated brochure and learn all you need to knowabout the parameters that really influence your weighing process and their impact on quality.

www.mt.com/minweigh

Data taken from an actual 60kg scale with a readability of 1g

Load on Scale(g)

Absolutemeasurement

uncertainty (g)

Relative measurement

uncertainty (%)

1 ±1.2 120

10 ±1.2 12

100 ±1.2 1.2

1000 ±1.2 0.12

10000 ±2.6 0.026

60000 ±11.8 0.020

Selection

5METTLER TOLEDO Good Weighing Practice™

Professional installationEnsures scale performance. Right from the start !

GWP® recommendation reportOnce the Evaluation and Selection Steps have been completed the METTlER TOlEDO weighing experts will generate a unique report describing the weighing sys-tem that best meets your specified requirements (see opposite). In addition to the appropriate weighing instrument, the GWP® recommendation describes also the most suita-ble installation type and scale verification procedures based on the regulations applicable to your process.

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For more information on IPac’s log onto

www.mt.com/ipac

IPacAn IPac provides the framework for installation and configuration of the weighing system. Furthermore it is the base for the first calibration and the training re-quired by the operators. Comply in no time with GMP qualification requirements (IQ, OQ,) or with the requirements of ISO, IFS or BRC.

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Proven performanceBullet-proof traceability

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CalibrationAll current quality management systems (GMP, ISO, IFS, etc.) request the user to document the performance of their instruments

Minimum Weight CertificateAdd a Minimum Weight Certificate to your usual Calibration Certificate and make your quality documentation bullet proof. That way you are in compliance with your process requirements all the time (see opposite).

Calibration, IPac and the Minimum Weight CertificateThe recipe to successful audits!

Find more about calibration and the Minimum Weight Certificate. Go to:

www.mt.com/ind-calibration

and to make them traceable to na-tional/international standards.Calibration verifies the effective per-formance of the instrument within its actual operating environment

with all external influences present. The resulting calibration cer-tificate documents this procedure bystating the Measurement Uncertainty of the weighing system (see page 4).

Calibration

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Monitoring performanceRouting testing to assure compliance

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The GWP® recommendation (see an example opposite) provides clear guidance as to:■ The type of test required■ The weights to be used■ The class of weight to be used ■ The frequency of the testing ■ The warning and control limits

for the routine testing

Routine operationThe day to day operation of your scale will impact its performance. This is why you will need to rec-alibrate it at regular intervals (e.g. once per year). Specially trained

technicians will verify and adjust your scale to its optimal perform-ance. But what happens between the calibrations? Will your scale deliver tomorrow the performance required to ensure quality?

GWP® gives you a clear recom-mendation about simple verifi-cation tests you can perform at regular intervals. The routine testing procedure will depend on the risks and the tolerance of your process.

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SOP for periodic eccentricity tests (routine tests)

Title: SOP for periodic eccentricity tests

Document No.: Author: METTLER TOLEDO Industrial

Number of pages: 4

Controls

Replacement document: N/A

Reason for revision: N/A

Release date: June 20, 2008

Release for routine operation

Reviewed by: Date: Signature:

Approved by: Date: Signature:

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Basic rules for using scales• Before using a scale, make sure the scale power was switched on for a

sufficient period of time (mentioned in the scale operating instructions).• Make sure the scale is leveled.• Minimize environmental influences, e.g. open windows, vibrations,

temperature changes or strong drafts.• Place objects gently on the scale platform.

Basic rules for handling weightsTest weights• Only commercial test weights with up to date calibration certificates can be used

for certifying the "traceability" of scale equipment.• Test weights should always be placed gently on a clean scale platform and

returned immediately in their storage place after use.• Test weights (since they are also part of measuring equipment) need to be

re-calibrated at specified intervals (ISO 9001).• Any incident, which might have affected the value of the test weight, should trigger

an immediate re-calibration. METTLER TOLEDO calibration services can offer a recommendation.

• Test weights should pe protected from shocks, scratches, dirt and any other external influence that might degrade their integrity.

How to store test weights• Test weights should be stored in their original box.• Test weights should be stored in a clean and dry room.

How to move weights• Small test weights should only be handled with appropriate tools such as forks or handles

(see METTLER TOLEDO’s accessories for weights).• Always use care when handling test weights, to avoid possible contamination or damage.

SOP for eccentricity tests Page 2

Eccentricity test

Preparation• Before the test is performed, the test weight must be acclimatized to the ambient

temperature of the scale.• Prepare a sheet to note the readings of the eccentricity test.

Test procedure• Place the test weight in the center (1) of the scale platform and tare (if required)• Place the test weight on position 2 at “Left front”

Note: Move the weights by lifting them; do not slide weights over the scale platform• Read the stable value from the display and note it• Repeat the measurements on positions 3, 4 and 5.

Evaluation• The largest reading (positive or negative) at any of the 4 corners (2 to 5)

is the eccentric load deviation.• Evaluate whether the eccentric load deviation exceeds the defined “Warning limit” 1).• Evaluate whether the eccentric load deviation exceeds the defined “Control limit” 2).

DeviationWarning limit 1) (where defined)• If the warning limit is exceeded, level the scale and repeat the test.• If the warning limit is exceeded again, report that the warning limit was not met to the appropriate

supervisor or the person responsible of the scale. Optionally, contact METTLER TOLEDO service organization for advice.

Control limit 2)

• If the control limit is exceeded, report the problem to the appropriate supervisor or the person responsible of the scale.

• Mark the scale as “out of control limits”.• Contact METTLER TOLEDO service organization for advice.

1) – Values within the warning limit: No action is necessary.

– Values between the warning and control limit are within the tolerance but must be kept under surveillance.

Corrective action may be appropriate, depending on the direction in which the values are changing.

2) – Values within the control limit, see 1)

– Values beyond the control limit show that weighing process is no longer under control and immediate action is therefore required.

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SOP for eccentricity tests Page 3

example

www.mt.com/GWP

Routine operation

Detailed Standard Operating Proce-dures (SOPs) are also available foreach of the recommended routine tests.

The GWP® recommendationincludes clear advice on testingprocedures – individually basedon your risk and process tolerance.

For more informationwww.mt.com/GWP

Mettler-Toledo AG CH-8606 GreifenseeTel. +41-44-944 2211Fax +41-44-944 3060

Subject to technical changes© 04/2009 Mettler-Toledo AGPrinted in SwitzerlandMTSI xxxxxxxx

Good DecisionsFor Safe Weighing

With Good Weighing Practice™ METTLER TOLEDO has developed a global guideline for the selection, operation and testing of weighing systems.

GWP® is a risk-based management system that puts all the current regulations like GMP, ISO, IFS, BRC, HACCP into a straightforward weighing practice.

Follow a simple program to assure compliance at any time.

Evaluate risks, ensure measurement security and save costs.

With GWP® you receive a tailored and easy to implement recommendation that will enable you to achieve the best weighing results at reasonable costs.