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Sartorius Weighing SeminarsQualified Weighing in Pharmaceutical LabsRegulations and Procedures to ensure best Weighing Accuracy in your Laboratory

• Qualified weighing, Avoid errors – and understand their daily impact on your weighing accuracy

Qualified weighing requires:

• Trained competent personnel

• Defined appropriate equipment and conditions

• Testing facility designed to minimiseproblems

35. Februar 2013

Qualified weighing requires:

• Regular calibration of measuringequipment

• According to accepted methods

• Use of Appropriate test & referencestandards – Calibration Weights

45. Februar 2013

Qualified weighing requires you to:

• Keep your balance clean

• Position the balance on firm surface

• Level the balance

• Protect the balance from drafts

• Especially air conditioning

• Never position in direct sunlight• Never position in direct sunlight

• Keep well away from all heat sources

5. Februar 2013 5

Avoid errorsThe correct place of installation?

• Mechanically and climatically stable

− stable temperature and humidity

− better on the first floor than on upper floors

• No vibrations

− especially low frequencies

Aircondition Open doors

Open windows

Sunlight

Air draft − especially low frequencies

< 10Hz should be avoided

− better to be closer to a wall, thanin the middle of the room

• Avoid installation in the exhaust areaof an air conditioner (disturbances and temperature)

5. Februar 2013 6

draft

unstabletable

Humidity

Hustleand Bustle

Vibrations

Avoid errorsThe correct place of installation?

• Not near to a window, no direct sunlight

− avoid infrared radiation; no direct light e.g.... a desk lamp

• Quiet place without hustle and bustle

Aircondition Open doors

Open windows

Sunlight

Air draft

5. Februar 2013 7

draft

unstabletable

Humidity

Hustleand Bustle

Vibrations

Avoid errorsElectrostatic charges

• Electrostatic charges create an acting force in addition to the weight of the sampleand container.

− This force is not constant. It’s influenced by humidity, the user and handling of samples and containers.

− The weight readout drifts in one direction. Values are non-repeatable.

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• Static electricity occurs on:

− substances or containers with low electrical conductivity

− large surfaces (plastic or glass containers, filters)

• The reasons are:

− internal friction in powders, external friction

− transfer of electrical charges by persons

− problem increases with decreasing humidity (<40%)

Avoid errorsElimination of electrostatic Charges

Internal solutions:

• Built-in ionizer inside the draft shield of semi-micro, analytical and 1mg-balances

External solutions

• Ionizer cube YIB01• Ionizer cube YIB01

• Stat Pen YSTP01 for small samplecontainers and membrane filters

95. Februar 2013

Avoid errorsMagnetic and magnetisable samples

The problem:Magnetic materials in samples or containers, such asnickel, iron, steel, generate force fields that act againstthe permanent magnet of the weighing system.• Weight values are stable, but non-repeatable.• Different values are displayed depending on the• Different values are displayed depending on the

position of the sample on the weighing pan.

How to avoid:• Do not weigh with magnetic stirrer inside the vessel• Perform demagnetization before weighing. Use a

nonmagnetic object to distance the sample from theweighing pan.

• Use Mu-metal (81% Ni and 19% Fe) foil as shielding.• Use below balance weighing

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Avoid errorsNon-level balance

One of the worst errors that occurs during

weighing is caused when the balance is

unlevel.

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αααα400µm

Avoid errorsNon-level balance

Example:If the balance is inclined only 400µm(Thickness of a business card) on one sidean incorrect measurement is produced:• That means, the mass of 200g is

displayed 0.37mg too low• The resulting error is greater than the

allowable tolerance of a 200g ± 0.3mg E2 calibration weight for an analytical balance.

Error calculation:md = m · cos α = 200g · cos (0,11°) = 199,99963gα = arctan (0.4mm/200mm)∆m = -0.00037g

5. Februar 2013 12

αααα400µm

Avoid errors – due tochanges in regional gravity influenced by changes in elevation andlatitude

• Ground floor 200.00000g

• First floor 199.99974g

• Difference 0.00026g

5. Februar 2013 13

Avoid errorsBalance warm up period

Balances need to be warmed up

(after new installation)

• Precision Balances (d >1 mg)approx. 30 min

• Analytical Balances (d> 0.1 mg)approx. 4 happrox. 4 h

• Semimicro Balances (d> 0.01 mg)approx. 12 h

• Ultramicro/Micro Balances (d> 0.001 mg)approx. 24 h

To avoid subsequent warm up periods :

• do not disconnect from power

• leave balance always in the standby-mode

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Was passiert wannkonkrete Empfehlungen

Avoid errorsCritical samples

Hygroscopic substances:

• Moisture absorption of powders

Efflorescent substances

• evaporation from the sample

• both cause a real weight change

• different results when weighing thesample at different times

• weighing value is drifting

How to avoid?

• use narrow-necked or covered vessels

• stabilise sample humidity in a desiccator

• work quickly5. Februar 2013 15

Bilder Tauschen

Avoid errorsNon acclimatized samples and tare containers

Sample containers are very often not

sufficiently acclimatised:

• temperature differences betweenweighing chamber and sample/samplevessels

• weighing results are varying• weighing results are varying

• weighing value is drifting:

− sample too cold: “weight increasing”

− sample too warm: “weight decreasing”

How to avoid?

• acclimatisation of sample/samplecontainers

• place weighing containers and sample inside weighing chamber beforeweighing5. Februar 2013 16

Avoid errorsHandling of samples, vessels and calibration weights

• handling the sample with hands raisestemperature and causes “gain-weight” effects

• this temperature effect can still berecognised after 10 minutes

• fingerprints falsify the real mass approx. • fingerprints falsify the real mass approx. 50 to 100µg

• additionally fingerprints can behygroscopic

• using the hand inside the draft shieldcauses additional turbulence and temperature effects

• weighing values are different, not stableand drifting

5. Februar 2013 17

Avoid errorsHandling of samples, vessels and calibration weights

How to avoid?

• never handle the sample withouttweezers or some other suitable grippingdevice

• always use gloves

• avoid working inside the draft shield, use• avoid working inside the draft shield, usea spatula which is long enough to keepthe hand outside

5. Februar 2013 18

Bilder Tauschen

Avoid errorsFilling containers

Ergonomic aspects:

• sometimes it’s difficult to weigh in thesample into small vessels, flasks ortubes

• the greatest problem is “spilling sampleon the weighing pan”on the weighing pan”

• the sample weight is displayed correctlybut the sample is not inside the container

How to avoid:

• Use special vial holder (Q-Grip)

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• Minimum sample weight according to USP

Minimum sample weight according to USPWeighing in the Pharmaceutical Laboratory

USP

Minimum Sample Weight Determination12,6 Kg

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dividedby 3!

Minimum sample weight according to USPUnited States Pharmacopeia – Chapter 41

USP 34 NF Chapter 41 Weights and

Balances

• determination of the minimum sampleweight

• the measuring uncertainty must beknown – three times the standardknown – three times the standarddeviation out of min. 10 replicantweighings

• measuring uncertainty (U) must notexceed 0.1% of the minimum sampleweight (M):

• the factor can be extended up to 0.00149

5. Februar 2013 22

001.0M

U ≤ UM *1000≤

SDU *3=

)49(001.0M

U ≤

Minimum sample weight according to USP United States Pharmacopeia - Interpretation

• the USP demands the practicaldetermination of the minimum sampleweight on site

• sample containers (vessels, flasks, ...) must be tared

• the smalest minimum sample weight• the smalest minimum sample weightis = 1000 digits

• the minimum sample weight is onlyapplicable for „assays“!!

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Minimum sample weight according to USP

• there are different interpretations of theUSP, Chapter 41

• Sartorius determins if a mass isapplicable

• OTHERS calculates the minimum weight to measured on the balance

vsto measured on the balance

• both procedures are globally used

• BUT, important is the interpretation of thelocal FDA inspector...

5. Februar 2013 24

OTHERS

Minimum sample weight according to USP Sartorius method to determine if appropriate

* 1000

=

OTHERS calculates

5. Februar 2013 25

from a Sartorius USP Certificate

=14 mg

Sartorius has verified a 15mg weight

Minimum sample weight according to USP The problem with the minimum weights...

In pharmaceutical labs in Europe you will

find 3 different minimum weights, that

should not be mixed up.

• 1. Min. Weight acc. European Guidlines forLegal Metrology (only Europe)

− Min Weight specification with legal

Example, Semi-Microbalance

min acc. EGLM = 1 mgmin acc. ISO (1%) approx. 10 mgmin acc. USP approx. 20 mg − Min Weight specification with legal

character – you must not fall below thisweight

• 2. Min Weight acc self defined tolerances

− on ISO 17025 based min weight, selfdefined, acc internal accuracy demands.

• 3. Min. Weight acc USP

− inspected by FDA – mutual characterin USA and for any manufacturerexporting to US

5. Februar 2013 26

min acc. USP approx. 20 mg

Minimum sample weight according to USP Why is it not possible to take the USP min from an ISO17025certificate?

• ISO17025 measuring uncertainty is

based on double standard deviation

(K=2), USP is based on three times

SD (K=3)

• ISO 17025 considers more parameters• ISO 17025 considers more parameterscompared to the USP (e.g. Linearity, weight tolerances, tempeture drift, rounding error).

5. Februar 2013 27

DKD

USP

Minimum sample weight according to USP My minimum sample weight is 10 mg. Which balance should I use?

• 10 mg is the absolute limit for a 5 decimal balance in “perfect” conditions

• The minimum sample weight is basedon the reproducibility of a balance and is significantly influenced by ambient conditions at the place of installation.

Recommendation:

Use a microbalance with a readability

of 1 µg.

• Specifying minimum weight to theabsolute limit it is not recommendedsince performance is not guaranteedover a balances complete life time.

5. Februar 2013 28

Minimum sample weight according to USP Typical* Minimum Sample Weights achieved by Sartorius Balances

Readability/Balance Type

0.1µg

1 µg

1 µg

10 µg

Minimum Sample Weight

1 mg

2 – 5 mg

5 – 15 mg

15 – 100 mg10 µg

0.1 mg

1 mg

* typical = based on Sartorius experience

15 – 100 mg

100 mg

1 g

5. Februar 2013 29

• Qualification of your laboratory balance

Equipment QualificationValidation - Qualification

• Validation ist the documented evidence that a process fulfills the defined needs in practical use.

• Qualification is the evidence that the equipment is able to fulfill it´s part in thisvalidated process

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• Therefore a balance is ne´ver validated – it is qualified to be used in a validatedprocess

Equipment QualificationAny equipment qualification needs 4 steps

DQ = Design Qualification

IQ = Installation Qualification

Technical specification forequipment (specification meet the user requirements)

Equipment is delivered and installed in accordance with the

Before Purchasing

At

5. Februar 2013 32

IQ = Installation Qualification

OQ = Operational Qualification

PQ = Performance Qualification

installed in accordance with the qualified design

Test of operational functions

Test of specified application

Ongoing performance tests and preventive maintenance

At installation

After installation

At regular intervals

Equipment QualificationDesign Qualification (DQ)

• DQ is the documented collection of activities that define the functional and operational specifications of the instrument and criteria for selection of the vendor, based on the intended purpose of the instrument

• It documents the design of the system and include :

− Functional specification

5. Februar 2013 33

− Functional specification

− Technical / performance specification for equipment

• A thoroughly executed DQ ensures that:

− Specification meet the user requirements

− Design is compliant with GMP and other regulatory requirements

− Details all equipment that must be ordered

Equipment QualificationInstallation Qualification (IQ)

• IQ is the documented collection of activities necessary to establish that an instrument is delivered as specified, is properly installed in the selected environment, and that this environment is suitable for the instrument

• Parts of the IQ

− Comparison of the equipment received with the purchase order

5. Februar 2013 34

− Comparison of the equipment received with the purchase order

− Equipment check for any damage.

− Documentation check for completeness

− Installation of hardware

− Initial cleaning

− SQ-min-Identification

Good to know:

Responsibility for IQ lies, as the whole EQ, with the user but activities can be

supported and carried out by the vendor.

Equipment QualificationOperational Qualification (OQ)

• OQ is the documented collection of activities necessary to demonstrate that an instrument will function according to its operational specification in the selectedenvironment

• OQ tests verify that the instrument

− meets manufacturer or users specification

5. Februar 2013 35

− meets manufacturer or users specification

− operating within established limits and tolerances

• Parts of the OQ

− Basic function check and check if the instrument powers up after it is switched on

− Calibration

− Operator training

Equipment QualificationPerformance Qualification (PQ)

• PQ is the documented collection of activities necessary to demonstrate that an instrument consistently performs under ‘full operational‘ conditions, and isappropriate for the intended use

• PQ tests using production materials

5. Februar 2013 36

• Tests include a condition or set of conditions encompassing upper and loweroperating limits

• PQ is ongoing

Good to know:

PQ is described as a separate activity, for balances it is appropriate to perform it in

conjunction with OQ

IQ/OQ-Service

• IQ/OQ documentation is based on a generic risk analysis

• Documentation consists of the IQ and OQ planning and of protocols for the IQ and OQ tests

• Documentation supports GLP, GMP and • Documentation supports GLP, GMP and FDA guidelines

• Accredited calibration certificates for ourbalances

• All documentation could easily beintegrated in existing QM systems

5. Februar 2013 37

Equipment Qualification

One main question remains:

• What should be tested during a IQ|OQ?

− Is it important to test the right colour of the equipment housing?

− Is it important to test if the right power supply was delivered?

− Is it important to issue a calibration certificate?

5. Februar 2013 38

− Is it important to issue a calibration certificate?

• How is the scope of test defined?

Other possibilities in the pharmaceutical industry for risk analysis

• Which is the right balance in my process (which measurement uncertainty isnecessary)

• What should be described in an SOP

• How often should the balance be calibrated

• How often is a maintenance needed

• Risk Analysis

5. Februar 2013 39

• Risk Analysis

Risk based approach

• Not each and every balance has to be qualified (Impact assessment)

• Not each and every function has to be qualified

• The most important thing is to focus on critical instruments and points

Focus on the critical instruments and critical points

• Reduce time

5. Februar 2013 40

• Reduce time

• Reduce costs

Risk based approach

• In August 2002, the FDA announced a significant new initiative that focuses on critical areas

• The new focus is that a quality management system needs to be based on a riskmanagement

5. Februar 2013 41

What does this mean?

• The idea is to stop the water can principle of validation and qualification

− to focus on critical aspects

• The level of effort, formality and documentation of the quality risk managementprocess should be commensurate with the level of risk

Risk analysis

• Risk analysis is a methodic approach to define critical parameters of equipment, systems and processes

• In the regulated industry (GLP and GMP environments), it is used for systematicidentification of potential risks and is a key integral component of quality riskmanagement

• Risk analysis is used as a key element in qualification projects. It helps to assess

5. Februar 2013 42

• Risk analysis is used as a key element in qualification projects. It helps to assessindividual project risk, critical functions of equipment and systems and define thescope of equipment qualification

• The basis for the requirement of performing risk analysis is found in ISO/IEC Guide 51:1999 and 73:2002, DIN EN ISO 14971:2000, the GMP Regulations of the FDA (Risk Based Approach) and in ICH (Q9 – Quality Risk Management)

• Risk based approach brings the user in the responsibility to reflect all qualityrelevant processes

Risk management

• Increases the understanding of the process

• Brings decisions on a better base

• Helps to establish actions that minimize the risk

• Gives the auditors significant information how a company works

• Provides important arguments why e.g. a calibration is done only once a week

5. Februar 2013 43

Risk EvaluationA risk of a potential failure can be evaluated by the probability of occurrence, the severity and the probability of detection.

Risk Priority Number RPN = O x S x D (can vary from 1 to 125)

O = Probability of occurrence

S = Severity

D = Probability of detection

11. August 2009 Seite 4

D = Probability of detection

O (occurrence rating):

1= Unlikely

2= Very low

3= Low

4= Moderate

5= Likely/High

S (severity rating):

1= No impact

2= Insignificant

3= Moderate impact

4= High impact

5= Catastrophic impact

D (detection rating):

1= High

2= Moderate

3= Low

4= Very low

5= Unlikely

Risk Evaluation (Example)

What is the risk that the balance is not leveled?

O (occurrence rating):

1= Unlikely

2= Very low

3= Low

S (severity rating):

1= No impact

2= Insignificant

3= Moderate impact

4= High impact

D (detection rating):

1= High

2= Moderate

3= Low

4= Very low

11. August 2009 Seite 4

3= Low

4= Moderate

5= Likely/High

4= High impact

5= Catastrophic impact

4= Very low

5= Unlikely

Risk Priority Number RPN = O x S x D = 4x4x3 = 48

Different kinds of risk analysis

• Failure Mode Effects Analysis (FMEA)

• Hazard Analysis and Critical Control Points (HACCP)

• Ishikawa

5. Februar 2013 46

Failure mode and effects analysis (FMEA)

• Originally Developed in the 1940’s for the US military and utilised in the Apollo space program

• Benefit is to find critical aspects and identify where to focus

• Steps of the FMEA:

• Potential failures (“Failure modes”) are detected

• Failures are analyzed “Effects analysis” (study of the consequences) and prioritized

5. Februar 2013 47

• Failures are analyzed “Effects analysis” (study of the consequences) and prioritizedaccording to how serious their consequences are, how frequently they occur and how easily they can be detected

• Actions are planed to prevent or reduce the severity or likelihood of failures

Failure mode and effects analysis (FMEA)

• Sartorius IQ|OQ Documents are based on a generic risk analysis

• Potential risks that are connected with the installation and operation of a laboratorybalances where evaluated with an FMEA .

• Equipment and application specific risks had not been taken into account.

5. Februar 2013 48

Knowledge about possible risks

To evaluate possible risks you have to identify them

• How big is the influence of a non-leveled balance?

• How big is the temperature depending drift of a balance?

• How big is the influence of a non optimized choice of vessel?

• How big is the influence of touching a vessel with bare fingers?• How big is the influence of touching a vessel with bare fingers?

• How big is the influence a temperature difference between sample vessel and thetemperature inside a draft shield?

Knowledge about possible risks

Once you know about the possible risks your are able to decide

• Is the risk important for my process at all?

• Can I reduce that risk by systems to compensate these effects

• Can I increase the probability of detection by available monitoring systems

Risk analysis

Regulatory compliance

Choice of best balance

Processintegration

Calibration weights Installation

Maintenance

Let us help you Advanced

PharmaCompliance

Page 1

User training

Calibration interval

Balance-Qualification (IQ/OQ)Warning - and action

thresholds

Calibration weights Installation

Correct weighing

The evaluation tool combines

Risk AnalysisMeasurement process

requirements

AdvancedPharmaCompliance

Page 3

Expert Input

Certificate

These are the • balance• accessories• services• procedures

you need!

Sartorius weighing specialist We

recommend...

Qualified weighing with Sartorius APC

Our weighing specialists will assist you by

• Evaluating your weighing process

• Determining the risks together with you

• Propose a weighing solution consisting out of

• type of balance• type of balance

• best choice of accessories

• recommendation for calibration weights and calibration cycles

• recommendation for warning and action thresholds


This documentation (Risk Analysis) is an essentiell part of your

Design-Qualification Advanced

PharmaCompliance

• Monitoring your laboratory balance

Monitoring the balance

Two things are important in daily work with the balance in a pharma lab:

• Monitoring the test equipment –making sure that the balance always is working within the defined tolerance limits

• Avoiding weighing errors caused by the user, the environmental conditions and the

5. Februar 2013 57

• Avoiding weighing errors caused by the user, the environmental conditions and thesample or sample container influences

Routine testing for constant safety – test equipment monitoring

Every Lab, which is accredited according to ISO/IEC 17025 or works according to the

GLP/GMP guidelines must regularly calibrate its testing equipment, and adjust as

necessary.

• Minimize the risk of erroneous measurements

• Fulfill the required process accuracy at any time

5. Februar 2013 58

• Fulfill the required process accuracy at any time

But, when and how often should calibration/adjustment be carried out on regular

basis?

• The length of the inspection interval depends on the risk of weighing, that means:

The customer has to clarify “how critical is the weighing value in the completeprocess”

• Based on that evaluation „warning levels“ and „action levels“ are determined

Monitoring test equipment– how often ?

Simple rule:• Daily, weekly or monthly in case the weight values are not critical• If weighing values are critical in the whole process, than

calibration should be done before every series of measurement

Page 5

Better:• Dynamic verification and adjustment of intervals based on

calibration results and defined warning and action thresholds

Monitoring test equipmentDynamic verification of calibration intervals

Time

Mea

suri

ng V

alue

Upper intervention limit

Target Value

Upper warning limit

Lower intervention limit

Lower warning limit

Time

Mea

suri

ng V

alue


Target Value

Upper warning limit


Lower warning limit

Increase IntervalIncrease Interval

Time

Mea

surin

g Va

lue


Target Value

Upper warning limit


Lower warning limit

Time

Mea

surin

g Va

lue


Target Value

Upper warning limit


Lower warning limit

Decrease IntervalDecrease Interval

case 1: increase intervals case 2: decrease intervals

Page 6

Time

Mea

surin

g Va

lue


Target Value

Upper warning limit


Lower warning limit

Time

Mea

surin

g Va

lue


Target Value

Upper warning limit


Lower warning limit

case 1: increase intervals

case 3: call service

case 2: decrease intervals

Monitoring test equipmentHow many and which weights to use ?

Often calibration is done only at one point

of the whole weighing range.

Better:

• Calibration should be performed at threeprominent points of the characteristic

Dis

play

ed W

eigh

ing

Valu

e

Near maximum

Working range

Dis

play

ed W

eigh

ing

Valu

e

Near maximum

Working range

prominent points of the characteristicbalance curve

• Near the minimum weight, to fulfill theregulatory requirements of USP

• In the working range, where the balanceis finally used; typically this is 10 to 20%

• Near the maximum load, because at thatpoint the absolute error is the highest

5. Februar 2013 61

Dis

play

ed W

eigh

ing

Valu

e

Near minimum weight

1 2 3

Dis

play

ed W

eigh

ing

Valu

e

Near minimum weight

1 2 3

Monitoring test equipmentThe balance is monitoring itself - isoCAL

• Sartorius Cubis and Secura seriesbalances are designed forPharmaceutical labs and includefunctions, which make monitoring easierfor the user

• Automatic calibration/adjustment functionisoCALisoCAL

• isoCAL maintains the accuracy of thebalance within an narrow tolerance band without testing efforts

5. Februar 2013 62

It corrects:

• deviations regarding to the sensitivity of the balance

• temperature influence (temperature limits can be set)

• compensates the influence of gravitation


• compensates the influence of gravitation (location, differences in altitude)

• air pressure, air density and humidity fluctuations (but it‘s not a compensation)

• aging effects of mechanic and electronic

5. Februar 2013 63

Model Temperature changes by After a time interval of

Ultra-micro, Micro, Semi-micro, Analytical 1mg-precision balances ≥1200g

1.5 °C 4h

1mg-precision balances ≤1200g10mg-precision balances ≥4200g

2°C 6h


5. Februar 2013 64

10mg-precision balances ≥4200g

10mg-precision balances ≤ 4200g 4°C 12h

100mg-precision balances 4°C 24h

The Balance is Monitoring ItselfDefault parameter settings of isoCAL for Cubis

The parameters can be changed by the user, but only in the direction to smaller

values.

• isoCAL has to be checked periodically by performing a calibration with an externalretraceable calibration weight. Best is, to test isoCAL at the same time that thebalance is calibrated, given by the defined test interval.

• An external calibration cannot be substituted by an internal calibration/adjustment

5. Februar 2013 65

• An external calibration cannot be substituted by an internal calibration/adjustmentfunction, however it is possible to expand the test intervals.

• isoCAL provides more safety in between the test intervals.

One of the worst errors that occurs duringweighing is caused when the balance isunleveled.

Monitoring test equipmentThe balance is monitoring itself – Q-Level

5. Februar 2013 66

αααα400µm


Example:If the balance is inclined only 400µm ( thickness of a businesscard) on one side an incorrect measurement is produced:

md = m · cos α = 200g · cos (0,11°) = 199,99963g

5. Februar 2013 67

αααα400µm

md = m · cos α = 200g · cos (0,11°) = 199,99963gα = arctan (0.4mm/200mm)∆m = -0.00037gThat means, the mass of 200g is displayed 0.37mg too lessThe resulting error is greater than the allowable tolerance of a 200g ± 0.3mg E2 calibration weight for an analytical balance.

The automatic, motorized leveling featured

on Cubis controls that the balance is

correctly leveled and performs the time

consuming alignment of the balance.

It is activated by pressing a start key or


It is activated by pressing a start key or

fully automatically in conjunction with the

isoCAL function

5. Februar 2013 68

For quick determination of the standard deviation to check the repeatability of results

Definition• Repeatability is the ability of the balance to display identical readouts when it is

loaded several times with the same weight under constant ambient conditions.• The standard deviation for a given number of measurements is used to quantify

the repeatability

Monitoring test equipmentThe balance is monitoring itself – ReproTEST

5. Februar 2013 69

the repeatability

• The “reproTEST” function automatically determines the repeatability of results(based on 6 individual measurements).

• The balance determines the most important specification in relation to the placeof installation – the pure performance without user influence.

• However, reproTest is no replacement for an external calibration!• The user can quickly decide if environmental conditions (air draft, vibrations) have

changed.

Thanks for your attentionThanks for your attention