Report on the CECED dishwasher ringtest - Institut für Landtechnik ...

Section of Appliance and Household technology
Institute of Agricultural technology
Rheinische Friedrich-Wilhelms-Universität Bonn
Prof. Dr. Rainer Stamminger
cand. oecotroph Daniel Pozzi
<strong>Report</strong> on the
CECED dishwasher ringtest
comparing 19 European laboratories performing
the European Energy Label - test for dishwashers
Version 0.9

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c○2003 University of Bonn

CONTENTS CECED DW Ringtest
Contents
1 Introduction 4
2 Organisation 5
2.1 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3 Participants and tiers 7
3.1 Machines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2 Course and observations . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.3 Minutes of the first evaluation meeting . . . . . . . . . . . . . . . . . 8
3.4 Minutes of the final evaluation meeting . . . . . . . . . . . . . . . . . 11
4 Methodology 14
4.1 Important changes of standard version EN50242:A3 . . . . . . . . . 14
4.2 Soiling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.3 Soil drying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.4 Machine loading schemes . . . . . . . . . . . . . . . . . . . . . . . . 14
4.5 Pretests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5 Results 16
5.1 Energy Label classification . . . . . . . . . . . . . . . . . . . . . . . . 16
5.2 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.3 Drying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.4 Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.5 Verification of laboratory conditions . . . . . . . . . . . . . . . . . . 28
5.5.1 Air temperature and humidity, water temperature and hardness 28
5.5.2 Reference machine operation . . . . . . . . . . . . . . . . . . 28
5.5.3 Laboratory equipment . . . . . . . . . . . . . . . . . . . . . 28
5.6 Noise emission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
6 Analysis 31
6.1 Cleaning outliers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
6.2 Drying outliers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
6.3 Repeatability and Reproducibility . . . . . . . . . . . . . . . . . . . 33
7 Conclusion 34
A Results of ringtest no.3 35
B Contact persons 35
B.1 Responsibility on behalf of CECED . . . . . . . . . . . . . . . . . . . 35
B.2 Ringtest coordination and evaluation . . . . . . . . . . . . . . . . . . 35
B.3 Participants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
C Cleaning and drying courses 36
1

LIST OF FIGURES CECED DW Ringtest
List of Figures
1 locations of participating laboratories . . . . . . . . . . . . . . . . . 6
2 the 3 tiers with numbered laboratories . . . . . . . . . . . . . . . . . 6
3 the loaded Memmert drying cabinet (courtesy WfK) . . . . . . . . . 15
4 Loading scheme of the Low machine (courtesy BSH) . . . . . . . . . 15
5 Energy Label cleaning ratios measured in 19 labs . . . . . . . . . . 17
6 Energy Label drying ratios measured in 19 labs . . . . . . . . . . . 18
7 Energy Label energy consumption efficiency measured in 19 labs . . 19
8 Cleaning performances . . . . . . . . . . . . . . . . . . . . . . . . . . 21
9 Cleaning water consumptions . . . . . . . . . . . . . . . . . . . . . . 22
10 cleaning time consumptions . . . . . . . . . . . . . . . . . . . . . . . 22
11 Cleaning results by load type . . . . . . . . . . . . . . . . . . . . . . 23
12 Reference machine performance . . . . . . . . . . . . . . . . . . . . . 24
13 Drying results by load type (corckery, glass and cutlery) . . . . . . . 26
14 Energy consumption during the cleaning tests . . . . . . . . . . . . 27
15 Noise emission: sound power levels compared . . . . . . . . . . . . . 30
16 H cleaning course by tier . . . . . . . . . . . . . . . . . . . . . . . . 37
17 L cleaning course by tier . . . . . . . . . . . . . . . . . . . . . . . . 38
18 H drying course by tier . . . . . . . . . . . . . . . . . . . . . . . . . 39
19 L drying course by tier . . . . . . . . . . . . . . . . . . . . . . . . . 40
List of Tables
1 Observations and incidents during the CECED Ringtest . . . . . . . 8
2 Results of the cleaning runs (averages) . . . . . . . . . . . . . . . . 20
3 Cleaning resource consumption . . . . . . . . . . . . . . . . . . . . . 21
4 Results of the drying runs . . . . . . . . . . . . . . . . . . . . . . . 25
5 Laboratory equipment . . . . . . . . . . . . . . . . . . . . . . . . . . 29
6 Grubb’s test for the cleaning runs . . . . . . . . . . . . . . . . . . . 32
7 Cochran’s test for the cleaning runs . . . . . . . . . . . . . . . . . . 32
8 Grubb’s test for the drying runs . . . . . . . . . . . . . . . . . . . . 32
9 Cochran’s test for the drying runs . . . . . . . . . . . . . . . . . . . 32
10 Repeatability and reproducibility . . . . . . . . . . . . . . . . . . . . 33
2

LIST OF TABLES CECED DW Ringtest
List of Abbreviations
BSH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Bosch-Siemens Hausgeräte
CECED . . . . . . . . . . . . . . . . European Committee of Manufacturers of Domestic Equipment
ITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Intertek Research and Testing Centre
KoV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Konsument Verket
LGA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Landesgewerbeanstalt Nürnberg
SLG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SLG Prüf- und Zertifizierungs GmbH
TNO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XXX
WfK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wäschereiforschung Krefeld
H, High . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . high-level performance machine
L, Low . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . low-level performance machine
R, Ref . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . reference machine
cons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .consumption
3

1 Introduction
CECED DW Ringtest
The European Energy Label indicates the effectiveness of electrical household appliances
to consumers (see 92/75/EEC). In the cases of dishwashers their cleaning
and drying performance are shown as well as the resources used. The declaration
is based on the European Norm EN 50242: Electric dishwashers for household use:
methods for measuring the performance, which gives detailed instruction concerning
the testing of the cleaning, drying, noise emission and resource consumption.
However, the latest revision of this standard (EN 50242prA3:2002) has never been
tested for its reproducibility. Therefore CECED, the European association of appliance
manufacturers, initiated the dishwasher ring-test as an European agreement of
manufacturers and independent laboratories. The ringtest not just aims to determine
the reproducibility of the norm, but also tries to facilitate expert knowledge
within the involved laboratories. Gathering experiences made during the tests, it
will help to reveal different interpretations of details and maybe point out missing
parts of the standard. Unlike earlier tests, this ringtest allowed a high number of
laboratories to participate, regardless of their experience.
4

2 Organisation
CECED DW Ringtest
The Ringtest is coordinated by University of Bonn, Section of Household and Appliance
technology, with technical support from the Ringtest machine manufacturers,
namely the dishwasher development departments of AEG/Electrolux Nürnberg and
BSH Dillingen.
2.1 Objectives
The CECED Ringtest aims to verify the improvements in the latest revision of EN
50242. To evaluate repeatability and reproducibility of the invoked tests several
European laboratories undergo the testing procedure. Any participating laboratory
is asked to perform standard-conform tests, i.e. dishwasher cleaning and drying tests
as described, exactly following the instructions.
To get an overview on the different laboratory conditions and working practises,
a questionnaire was sent to the participants. Data asked for was for example the
laboratory equipment, that is the measurement devices, reference machines, soils
used and further information.
The standard tests are to be carried out with two dishwasher models, one of higher
and one of lower performance (see 3.1).
A minor objective is to perform noise emission test according to 60704-2-3, where
facilities provide the equipment.
2.2 Actions
The following actions have been undertaken (in chronological order):
• Construction of the Ringtest machines
• Grouping of the participants into tiers
• Coordination of testing and transports
• Arranging visits between labs
• First evaluation meeting after gathering results from 15 labs in Bonn (July
2003)
• Data evaluation and analysis
• Second evaluation meeting in Bonn (October 2003)
• Final evaluation and report release
5

2.2 Actions CECED DW Ringtest
North
5
West
2
South
1
Figure 1: locations of participating laboratories
4 7 9 14 18
10 6 11 17 16 19
3 13 8
12 15
Figure 2: the 3 tiers with numbered laboratories
6

3 Participants and tiers
CECED DW Ringtest
To grant the participants’ anonymity every lab is referred by a number. The list
below is ordered alphabetically and does not correspond to the given numbers. The
following manufacturer and testing institutes have taken part in the Ringtest:
• Antonio MERLONI (Italian manufacturer)
• ARCELIK A.S. (Turkish manufacturer)
• Bauknecht Whirlpool (German manufacturer)
• SMEG Bonferraro(Italian manufacturer)
• Bosch-Siemens Hausgeräte Dillingen/Do. (German manufacturer)
• CTTN-IREN (French testing institute)
• ELCO BRANDT (French manufacturer)
• Electrolux Solaro (Italian manufacturer)
• Electrolux Therma (Suisse manufacturer)
• ITS (British testing institute)
• Konsumentverket (Swedish testing institute)
• LCIE (French testing institute)
• Landesgewerbeanstalt Nürnberg (German testing institute)
• MERLONI Elettrodomestici (Italian manufacturer)
• MIELE (German manufacturer)
• SLG (German testing institute)
• TNO (Dutch testing institute)
• VDE (German testing institue)
• WfK Institut (German testing institute)
In the first meeting it was agreed to divide the participants into three tiers according
to the European region they reside (North, West, South). See figure 2.
It should be noticed though, that the original sequence of participants could not be
maintained due to unexpected incidents. The course has been rearranged several
times and finally did not separate participants by region anymore.
3.1 Machines
The CECED dishwasher ringtest is the first to test two machines against a reference
machine. AEG Electrolux therefore agreed to build four similar machines specially
for the ringtest, which should perform above the reference machine in all relevant
aspects. BSH agreed to build a set of four machines which were intended to perform
below the reference level.
This way three tiers can be equipped with a high and a low performance machine
each, while having one reserve machine of each type.
7

3.2 Course and observations CECED DW Ringtest
Table 1: Observations and incidents during the CECED Ringtest
date incident
October 2002 one machine arrives unpacked at ITS (UK)
October 2002 Arcelik A.S. visit at ITS (UK)
October 2002 Uni Bonn visit at BSH
October 2002 BSH: problems with energy measurement of the H machine
October 2002 AEG: one machine now being sent for three weeks
November 2002 Turkish customs delay machine delivery for three weeks
November 2002 Uni Bonn visit at Electrolux Solaro (I)
January 2003 water softener defects in one L machine, being replaced in all
May 2003 Uni Bonn visit at Merloni Elettrodomestici (I)
August 2003 one L machine arrives damaged at WFK (D), but remains functional
3.2 Course and observations
The course of the machines and testing can be seen in figure 2. Extraordinary
incidents are listed in table 1. The original intention to increase share of expert
knowledge by arranging visits between participants has not been realized in the
desired extend, as the call for mutual visitors was not sufficiently responded.
3.3 Minutes of the first evaluation meeting
Participants (unordered list):
• Hans Beer (BSH)
• Christoph Türck (VDE)
• Rainer Brenk (VDE)
• Lothar Köhler (SLG)
• Franka Möhring (SLG)
• Winfried Steiner (Electrolux)
• Stefan Schlup (Electrolux)
• Ayla Kuran (Arcelik)
• Ingrid John (Bauknecht)
• Jeremy Owens (ITS)
• Nicola Gaudiano (Merloni El.)
• Gnther Ennen (Miele)
• Gernot Walzberger (LGA)
• Christine Gluth (LGA)
• Massimo Giaffreda (Electrolux)
• Rainer Stamminger (Uni Bonn)
• Daniel Pozzi (Uni Bonn)
8

3.3 Minutes of the first evaluation meeting CECED DW Ringtest
The following text are the original minutes sent to all participants, excepted for
some confidential information:
Rainer Stamminger opened the meeting and welcomed all participants.
Although the Ringtest is not finished (as planned) and some more laboratories
still have to test the machines he explained the two purposes
for having this meeting now:
1. to have a first view on the data and to agree on what additional
data have to be collected and what additional points should be
included in the final evaluation.
2. to agree on the essential points for the first presentation of the
outcome at the coming EEDAL-conference in Torino, Oct 1.-3.
As anonymity of the testing lab identity is for granted when data are
shown to the outside, it was felt helpful to know the identity of the lab
when discussing about the results. As the Ringtest was also intended to
help CECED to identify external labs which could act as a reference for
disputes about declaration values in making a tour around the table all
labs present agreed to disclose their identity. It was assumed that also
labs not participating at the meeting would accept this openness. (If
this is not the case, please testify this to D.Pozzi within 14 days after
receiving these minutes R.S.)
In going through the data presented by D.Pozzi following actions (A)
or conclusions (C) or recommendations for change of the standard (S)
were noted:
• all labs not having noted the real measured ambient conditions in
the data sheets are kindly requested to send the missing data (A:
many labs)
• following labs were noted to have natural prepared water: LGA,
Whirlpool, Elux Solaro, BSH, Merloni
• following labs were noted to have artifical water: Miele, ITS, Arcelik,
Elux Therma, SLG, VDE
• labs not noted are kindly requested to send the relevant information
(A: ???)
• lab 2 and 5 were noted to have quite high variation in reference
machine cleaning performance. Is this normal in these labs?? (A:
lab 2 and lab 5)
• Although the repeatability seems to be o.k. the reproducibility
of the cleaning performance test seems to be too high, as it might
happen that machine L is measured in some lab as good as machine
H in another lab, if no evidence of outlier behaviour is found in the
coming analysis (C).
• There should not only be given limits for the average behaviour of
the reference machine, but also limits for each individual cycle. (S)
• There are significant difference measured in the time used for some
machines in some labs (especially lab 5). This is seen as a clear
indication that the water fet to the machine is too cold. These labs
are requested to check the water temperature at the connection
point of the inlet pipe and to report the measured temperature
back (A: lab 5 + others).
9

3.3 Minutes of the first evaluation meeting CECED DW Ringtest
• It was questioned if drying tests in lab 11 were done in parallel to
the cleaning performance test (A: Lab 11 testify)
• On drying, results of machine H are spread around 3 energy label
classes while machine L covers 2 classes. (C)
• A statistical outlier test should be done on all relevant data (indices).
(A: Uni Bonn)
• <strong>Report</strong> (if not jet done) type and serial number of Memmert or
other oven used and kind of shelf used to place the dishes (A: all)
• The questionnaire should be returned not later than end of July
(A: all, if not jet done)
• <strong>Report</strong> about energy measuring equipment use: report type and
producer and if it is fulfilling IEC 61036 class 1 requirements (A:
all)
• Temperature graphs for all cycles should be sent (A: all). AEG
(Steiner) and BSH (Beer) will check and compare with their experience
• Photographs of all crockery articles used should be sent (A: all)
• As evidence is reported that the surface of porcelain is changing,
it is proposed to use the crockery only after the 10th run. More
evidence has to be given! (S)
• For clarification it should be made clear, that the drying procedure
in the oven should be 2 hours after closing the door of the oven (S)
• A last call should be tried to include missing test labs, especially
from Scandinavia. (A: Uni Bonn)
• DWs having finished testing should be sent back to Uni Bonn. AEG
volunteered to re-test their machines. BSH has no chance due to
too much other work. Another solution to verify should be found
(A: Beer)
• It was agreed not to distribute the data shown at the meeting, but
to keep them confidential up to the next meeting, which was agreed
to be at the 24th of September 2003 (in Bonn).
For the presentation of Mr. Beer at the EEDAL conference following
messages from the ring-test were agreed:
• energy measurement is not too bad in reproducibility
• cleaning and drying performance need improvement in uncertainty
• within one lab, the ranking stays always the same, but absolute
values may be misleading
• reproducibility of the testing method must be improved or outliers
(and the reason for being outlier) identified
• regular ring-tests are needed (at least all two years) to verify the
comparability of the procedures in all labs.
10

3.4 Minutes of the final evaluation meeting CECED DW Ringtest
3.4 Minutes of the final evaluation meeting
The meeting took place on October 28th, 2003. The following persons attended the
meeting (unordered):
• S. Leach (ITS)
• H. Beer (BSH)
• C. Türck (VDE)
• R. Brenk (VDE)
• N. Gaudiano (Merloni)
• H. Nilsson (KoV)
• I. John (Whirlpool)
• A. Ophüls (WfK)
• U. Pieper (Miele)
• F. Mack (Electrolux)
• W. Vögl (Electrolux)
• M. Giaffreda (Electrolux)
• A. Sofiatti (Bonferaro SMEG)
• D. Pozzi (Uni Bonn)
• R. Stamminger (Uni Bonn)
Rainer Stamminger opened the meeting in welcoming all participants.
As anonymity of the testing lab identity is for granted when data are shown to the
outside, it was agreed again to open the identity of the lab when discussing about
the results. A list to identify each lab number was distributed.
Data gathered throughout the ring-test had been analysed by D.Pozzi and where
discussed at the meeting. A hand-out of these results was forwarded to all participants.
In going through the data presented following actions (A) or conclusions (C) or
recommendations for change of the standard (S) were noted:
• When results are published, they should be both with and without outlier, as
outlying laboratories may still exist in reality (A: Pozzi)
• Time of program in reference machine (R): lab 5 and 12 measured too high.
Lab 12 may have taken the offposition instead of the end position. No explanation
is found for Lab 5 (A: lab 5)
• Program time for high-level machine (H) should be between 150 and 170
minutes. Labs 5, 16 and 17 are out of this range!
• Program time for low-level machine (L) has changed with new regeneration
cycle programming. All labs are within the tolerance limits.
• Cleaning performance of R: lab 16 and 19 are out of tolerance.
11

3.4 Minutes of the final evaluation meeting CECED DW Ringtest
• Cleaning performance of R on different items show big differences between
labs. It was proposed to define individual cleaning performance limits for the
reference machine depending on the kind of items (glass, cutlery, crockery)
(S)
• Especially the cleaning performance of the milk in glasses seems to vary a lot.
It was proposed to collect individual data from all laboratories (pictures and
rating according to colour scale) of glasses before and after drying in the oven.
(A: Proposal for collection by N. Gaudiano, collection and comparison by Uni
Bonn)
• Cleaning of glasses showed increased spread in laboratories 5, 16, 17 and 19!
• Mrs. Pieper reports about their experience not to keep milk stored in the
refrigerator over weekends.
• Cleaning of cutlery: H is always higher than L, but R shows no clear trend.
Perhaps the separate cutlery basket of R on top of the machine is influenced by
other factors as in normal machines. (A: Miele to analyse influencing factors).
Labs 6, 12 and 16 show extremely high values of 5 for R!
• Cleaning crockery: H is always higher than L, but R is sometimes higher than
H and lower than L in other labs!!!
• Cleaning: Repeatability values for H and L are lower than R when taking
absolute cleaning values, but reproducibility is lower when looking on ratios
(so considering R) (C)
• Repeatability and reproducibility should be calculated also separately for
glasses, cutlery and crockery.
• If possible an analysis of the cleaning results for each type of soil should be
done (A: Pozzi)
• Water consumption: Lab 15 is out of tolerance in R
• Energy consumption: Lab 12 is out of tolerance on R
• There is no obvious correlation of time, water and energy consumption and
cleaning performance of R
• Lab 12 reports too low ambient temperature (??) of R
• Energy in cleaning tests: repeatability is very good, but reproducibility is two
to three times higher! Nevertheless 4% reproducibility is a good value! R has
highest value for % reproducibility (A: Miele to check sources). The tolerance
given in the standard for the energy consumptions should be % drastically
reduced (C, S)
• Drying: Lab 11 is identified as outlier. Also lab 10 and 19 are too high for
L. Drying results of L may be influenced by change in softening procedure,
but no clear indication was found for this in the data. Ambient conditions in
lab 11 and 19 are too low. High variation of L may be also explained by the
lower absolute values as this needs to be done between scoring 0 and 1. While
on better drying machines the scoring of 2 is more easy to identify. A better
differentiation of the drying performance in a 5 glass scale may help (S).
12

3.4 Minutes of the final evaluation meeting CECED DW Ringtest
• Noise: In absolute values there are differences of 5 dB. But difference between
H and L is more constant. Lab 11 shows no difference! Different usage of
the enclosure may explain some of the absolute differences. Lab 8 measured
without enclosure.
• General conclusion 1: Tolerances given in the standard for energy consumption
and drying performance are o.k., but too small for cleaning performance.
• General conclusion 2: This kind of ring-test is very useful as laboratories
get the chance to compare themselves which others. The outcome of this ringtest
must trigger all laboratories to check their internal procedures (A: all).
A next ring-test was seen as useful to be started next year! (A: Beer).
• General conclusion 3: The data and outcome of this Ringtest should be
forwarded to all relevant standardisation bodies, especially UK513.5, CEN-
ELEC TC59X WG2 and IEC 59A with the request to take up the learning
and think about necessary changes of the standard.
13

4 Methodology
CECED DW Ringtest
4.1 Important changes of standard version EN50242:A3
• air humidity tolerance is reduced to (55± 5)%, water hardness shall be 2.5 ±
0,5 mmol/l
• no damage load pieces shall be used, pieces shall be used for 200 ± 20 cycles
• soil application details
• dishwasher operation and assessment details (e.g. to evaluate cutlery last)
Participating laboratories were asked in the first mailing to perform the test for
Energy labelling according to the lastest official version of the standard including
the CECED code of testing. As the latest change of the standard (EN 50242:A3)
did get officialised only by December 1st, 2002, some laboratories may not have
strictly followed this version.
4.2 Soiling
The procedure of soiling the loads for cleaning tests has to be done according to EN
50242, section 6.4. Preparation and application of the soils (e.g. eggs, oat flakes,
margarine, minced meat, milk) is standardised, though the source respectively supplier
of the foodstuff is a recommendation only. Where available, the suppliers
where asked for.
4.3 Soil drying
After applying the soils the crockery undergoes the oven drying procedure for two
hours to simulate stubborn soilings. Since the oven (e.g. see figure 3) drying has a
strong influence on the later test outcomes, model data (see table 5) and temperature
logs have been requested by Uni Bonn. The intial idea to use tempreature
indicator strips was not feasible. However, after communicating the issue with all
participants, a recommendation was issued how to perform the loading procedure.
Glasses (soiled with milk) are put into a microwave to brown the milk. See figure 11
for a graphical comparison of glass cleaning performance. Additional examinations
may be needed at this point.
4.4 Machine loading schemes
Figure 4 shows how the soiled parts have be be inserted into the L machine. Similar
instructions exist for the H and R machines, and are of course available to the
participants.
4.5 Pretests
To assure proper test machine operation, two preliminary cleaning runs without
soils have to be performed, data measured and sent to Uni Bonn for confirmation.
This is done to exclude the possibility to runs test with machines that have been
damaged during the transports.
14

4.5 Pretests CECED DW Ringtest
Figure 3: the loaded Memmert drying cabinet (courtesy WfK)
A B
a
Eier
eggs
Milch
milk
Tee
b tee
Hackfleisch
c minced meat
d
de
e
f
g
Haferflocken
oat flakes
Spinat
spinach
Margarine
margarine
en
Hinweise für Vergleichsprüfungen Information on comparability Remarques concernant les essais
nach
tests implemented in compliance comparatifs selon EN 50242
EN 50242
with EN 50242
Rangement de la vaisselle selon cette norme.
Einordnung nach Normvorgabe
Einordnungsbeispiel: siehe Bilder A – D
Fassungsvermögen: 12 Maßgedecke
Vergleichsprogramm: Eco
Klarspülereinstellung: 4
Appliance loaded in accordance with standard
specifications.
Example of loaded dishwasher:
see Figs. A – D
Capacity: 12 place settings
Exemple de rangement: figures A – D
Contenance: 12 couverts standard
Programme utilisé pour la comparaison: Eco
Réglage du liquide de rinçage: 4
Quantité de détergent de référence: 30 g
Referenzreiniger: 30 g
Comparability programme: Eco
Si le panier supérieur est réglable en hauteur,
Bei höhenverstellbarem Oberkorb muss der
Oberkorb in die obere Stellung eingesetzt
werden.
Rinse-aid setting: 4
Reference cleaner: 30 g
Height-adjustable top-basket 15
must be inserted
installez-le dans la position supérieure.
S’il existe des déviations par rapport aux
contrôles comparatifs selon EN 50242 portant
Bei Abweichungen von den
in the uppermost position.
sur, par ex., le degré de salissure, le type de
Vergleichsprüfungen nach EN 50242, z.B. If the comparability tests do not comply fully vaisselle et de couvert, contactez le fabricant
Figure 4: Loading scheme of the Low machine (courtesy BSH)
C
fr
D

5 Results
5.1 Energy Label classification
CECED DW Ringtest
The following graphs display the results classified according to the Energy Label
(cleaning performances in figure5, drying performance in figure 6, energy consumption
in figure 7). Class borders are indicated as dotted lines. For calculation and
further information refer to EN 50242:A3.
Water consumption and noise emission are not classified. The average amount of
consumed water during the cleaning tests can be seen in table 3 and figure 9. Noise
emission test results are briefly displayed in figure 15.
16

5.1 Energy Label classification CECED DW Ringtest
© Uni Bonn 2003
Energy label - cleaning ratio
A
1,300
1,231
1,200
1,141
1,105 1,104
1,116
1,111
B
1,100
1,088
1,080
1,100
1,062
1,046
1,047
1,023
1,011 1,008
1,000
1,002 0,998
0,984
0,973
0,982
1,000
C
0,970
0,954
0,948
0,946
0,955
Figure 5: Energy Label cleaning ratios measured in 19 labs
17
0,937
0,935
0,913
0,918
0,906
0,901
0,898
0,905
0,883
0,900
0,856
0,875
0,875
D
0,800
0,700
0,600
Lab 19
Lab 18
Lab 17
Lab 16
Lab 15
Lab 14
Lab 13
Lab 12
Lab 11
Lab 10
Lab 09
Lab 08
Lab 07
Lab 06
Lab 05
Lab 04
Lab 03
Lab 02
Lab 01
machine H machine L class A limit class B limit class C limit

5.1 Energy Label classification CECED DW Ringtest
Energy Label - drying ratios
© Uni Bonn 2003
A
1,200
1,191 (both outlier)
1,134
1,119
1,084
1,100
1,068
1,077
B
1,059 1,057
1,059 1,071
1,062
1,052
1,055
1,041
1,044
1,041 1,047 1,045
1,045
1,019
1,000
0,989
1,000
0,947
0,932
0,920
C
0,903
Figure 6: Energy Label drying ratios measured in 19 labs
0,894
18
0,890
0,886 0,895 0,897
0,900
0,835
0,844
0,832
0,826
0,814
0,800
0,769
D
0,754
0,700
0,600
Lab 19
Lab 18
Lab 17
Lab 16
Lab 15
Lab 14
Lab 13
Lab 12
Lab 11
Lab 10
Lab 09
Lab 08
Lab 07
Lab 06
Lab 05
Lab 04
Lab 03
Lab 02
Lab 01
machine H machine L class A limit class B limit class C limit

5.1 Energy Label classification CECED DW Ringtest
Energy Label - energy efficiency
© Uni Bonn 2003
1,40
1,38
1,37
1,36
1,36
kWh
C
1,32
1,32 1,32 1,32
1,32 1,32
1,31
1,30
1,30
1,30
1,30
1,27
1,26
1,26
1,25
1,25
1,23
1,22
Figure 7: Energy Label energy consumption efficiency measured in 19 labs
19
1,20
1,19
1,19
1,19
1,20
1,18
1,18 1,18
1,17
1,16
1,16
1,16 1,16
1,16
B
1,14
1,14
1,14
1,13
1,10
A
1,00
Lab 19
Lab 18
Lab 17
Lab 16
Lab 15
Lab 14
Lab 13
Lab 12
Lab 11
Lab 10
Lab 09
Lab 08
Lab 07
Lab 06
Lab 05
Lab 04
Lab 03
Lab 02
Lab 01
machine L machine H class A limit 1,06 kWh class B limit 1,25 kWh

5.2 Cleaning CECED DW Ringtest
Cleaning Table results 2: overview Results of the cleaning runs (averages)
Cleaning results
Cleaning ratios
Lab H H Sx L L Sx Ref R Sx H SI L SI
Lab 01 4,00 0,240 3,44 0,101 3,59 0,125 1,111 0,048 0,935 0,024
Lab 02 3,92 0,078 3,33 0,054 3,63 0,156 1,080 0,038 0,918 0,046
Lab 03 3,78 0,083 3,20 0,077 3,66 0,029 1,047 0,027 0,875 0,016
Lab 04 4,10 0,092 3,52 0,044 3,58 0,025 1,141 0,023 0,982 0,010
Lab 05 4,30 0,119 3,34 0,117 3,50 0,209 1,231 0,059 0,955 0,054
Lab 06 3,77 0,073 3,36 0,054 3,71 0,027 1,002 0,023 0,905 0,010
Lab 07 3,36 0,045 3,03 0,149 3,37 0,125 0,998 0,036 0,898 0,028
Lab 08 4,00 0,101 3,53 0,175 3,76 0,130 1,062 0,017 0,937 0,039
Lab 09 3,32 0,105 2,99 0,075 3,41 0,045 0,973 0,030 0,875 0,015
Lab 10 4,01 0,046 3,24 0,143 3,59 0,071 1,116 0,014 0,901 0,038
Lab 11 3,54 0,103 3,07 0,184 3,48 0,186 1,046 0,022 0,883 0,033
Lab 12 4,12 0,108 3,53 0,273 3,72 0,017 1,105 0,033 0,946 0,073
Lab 13 3,84 0,063 3,21 0,123 3,75 0,048 1,023 0,019 0,856 0,033
Lab 14 3,99 0,040 3,56 0,083 3,61 0,025 1,104 0,012 0,984 0,026
Lab 15 4,01 0,056 3,46 0,108 3,65 0,159 1,100 0,051 0,948 0,055
Lab 16 4,46 0,120 4,10 0,224 4,48 0,105 1,000 0,039 0,913 0,051
Lab 17 4,13 0,115 3,68 0,080 3,80 0,061 1,088 0,036 0,970 0,024
Lab 18 3,57 0,094 3,37 0,157 3,54 0,161 1,011 0,056 0,954 0,076
Lab 19 4,13 0,233 3,71 0,197 4,09 0,098 1,008 0,044 0,906 0,052
Average 3,913 0,101 3,404 0,127 3,680 0,095 1,066 0,033 0,923 0,037
Sr 0,114 0,141 0,112 0,036 0,042
SR 0,317 0,294 0,270 0,071 0,053
Sr % 2,91% 4,14% 3,04% 3,36% 4,52%
SR% 8,10% 8,64% 7,34% 6,66% 5,74%
After recalculation (without Lab 05)
Average 3,91 0,10 3,40 0,13 3,68 0,09 1,056 0,03 0,92 0,04
Sr 0,1137 0,141 0,112 0,034 0,042
SR 0,317 0,294 0,27 0,058 0,053
Sr % 2,91% 4,14% 3,04% 3,22% 4,52%
SR% 8,10% 8,64% 7,34% 5,49% 5,74%
5.2 Cleaning
Results of all cleaning performance tests are shown in figure 8 and in table 2 above.
which also contains details like water and energy consumption.
20

5.2 Cleaning CECED DW Ringtest
Table 3: Cleaning resource consumption
Water consumption[l] Energy [kWh] Time elapsed [min] Time dev
Lab H sH L (old) L (new) sL R* sR H sx L sx R* sx H L Ref H L Ref
Lab 01 15,4 1,1 13,2 0,2 27,2 0,2 1,19 0,010 1,25 0,038 1,83 0,016 161 64 80 2 1 0
Lab 02 14,6 0,1 13,4 0,1 27,7 0,1 1,20 1,32 0,011 1,80 0,004 155 67 83 2 0
Lab 03 14,5 0,4 13,8 0,2 26,7 0,1 1,19 0,004 1,32 0,036 1,73 0,025 154 66 82 1 0 0
Lab 04 15,5 1,1 13,6 0,1 27,9 0,0 1,18 0,005 1,31 0,010 1,84 0,011 161 66 83 0 0 0
Lab 05 15,4 0,2 13,7 0,2 28,0 0,1 1,18 0,005 1,26 0,015 1,85 0,015 179 69 84 0 0 0
Lab 06 15,2 0,9 13,4 0,2 26,9 0,2 1,22 0,004 1,30 0,030 1,90 0,011 157 66 81 4 1
Lab 07 14,5 1,2 17,2 0,2 27,1 0,1 1,14 0,006 1,37 0,014 1,90 0,009 151 71 81 1 0
Lab 08 15,2 0,9 18,4 0,8 28,0 0,5 1,16 0,013 1,36 0,011 1,82 0,013 161 74 81
Lab 09 15,6 0,9 18,3 0,6 27,5 0,1 1,17 0,017 1,32 0,032 1,82 0,032 156 68 81 2
Lab 10 15,0 0,4 13,7 0,1 27,9 0,0 1,18 0,009 1,32 0,025 1,90 0,009 159 67 81 4 1 0
Lab 11 15,0 0,9 18,1 0,4 27,2 0,4 1,14 0,005 1,32 0,020 1,83 0,018 156 69 81 2 1 0
Lab 12 15,5 1,5 17,1 0,6 28,5 0,5 1,16 0,004 1,30 0,029 1,59 0,009 155 70 89 5 1
Lab 13 15,0 0,9 13,3 0,2 28,0 0,1 1,23 0,005 1,32 0,017 1,81 0,012 159 67 81 3 1 0
Lab 14 16,1 1,0 17,3 0,2 27,1 0,2 1,16 1,36 0,024 1,89 0,003 163 72 81 1 0
Lab 15 14,9 0,8 31,8 0,5 1,19 0,007 1,38 0,014 1,86 0,029 153 69 94 1 1 2
Lab 16 15,8 0,9 26,7 0,1 1,16 0,015 1,25 0,015 1,82 0,007 145 67 81 1 1 0
Lab 17 14,8 0,9 18,0 27,1 0,1 1,14 0,008 1,27 0,008 1,82 0,005 148 68 80 0
Lab 18 15,3 1,1 18,5 27,1 0,1 1,13 0,008 1,26 0,008 1,63 0,015 156 70 79 2 1 0
Lab 19 15,6 0,8 16,9 27,3 0,0 1,16 0,008 1,30 0,008 1,68 0,013 150 80 81 2 1
Average 15,2 13,5 17,7 27,5 1,17 0,01 1,31 0,02 1,80 0,01 159,1 68,4 82,0
Sr 0,008 0,040 0,022 0,016 6,7 2,7 2,3
SR 0,028 0,044 0,090
Sr % 0,71% 1,64% 0,86%
SR% 2,39% 3,36% 4,99%
Cleaning index
5,00
4,00
3,00
2,00
1,00
0,00
cleaning performances
© Uni Bonn 2003
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Ref High Low Avg Ref Avg High Avg Low
Figure 8: Cleaning performances: single runs results (cross dots) and averages (bars)
21

5.2 Cleaning CECED DW Ringtest
water consumption [l]
30,0
25,0
20,0
15,0
10,0
Cleaning water consumption
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Water [l] H Water [l] L (old) Water [l] L (new) Water [l] R*
31,8
© Uni Bonn 2003
Figure 9: Cleaning water consumptions. L machine electronics have been replaced during
the test, causing water consumption to increase about 3,5 liters.
170
160
150
140
130
120
110
100
90
80
70
60
64
179
Cleaning time elapsed [min]
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Time elapsed [min] H Time elapsed [min] L Time elapsed [min] Ref
Figure 10: cleaning time consumptions
22
89
94
145
© Uni Bonn 2003
80

5.2 Cleaning CECED DW Ringtest
cleaning index
cleaning index
cleaning index
5,00
4,50
4,00
3,50
3,00
2,50
2,00
1,50
1,00
0,50
0,00
5,00
4,50
4,00
3,50
3,00
2,50
2,00
1,50
1,00
0,50
0,00
5,00
4,50
4,00
3,50
3,00
2,50
2,00
1,50
1,00
0,50
0,00
Cleaning Crockery
Labs 1-19
H crockery Ref crockery L crockery
Cleaning Glass
H glass ref glass
Labs 1-19
L glass
Cleaning cutlery
H cutlery Ref cutlery L cutlery
Labs 1-19
© Uni Bonn 2003
© Uni Bonn 2003
© Uni Bonn 2003
Figure 11: Cleaning results by load type (crockery, glass and cutlery)
23

5.2 Cleaning CECED DW Ringtest
Cleaning index
5,00
4,50
4,00
3,50
3,00
2,50
2,00
1,50
1,00
0,50
0,00
Cleaning performance of the reference machine
Labs
total Ref crockery Ref cutlery Ref glass
© Uni Bonn 2003
Figure 12: Reference machine performances (total as line) with single load results (dots)
24

5.3 Drying CECED DW Ringtest
Table 4: Results of the drying runs
Drying performances std dev
Drying ratios
Lab H L R H Sli L Sli R Sli H SI L SI
Lab 1 0,94 0,72 0,88 0,027 0,025 0,022 1,062 0,037 0,826 0,045
Lab 2 0,89 0,69 0,78 0,030 0,024 0,023 1,134 0,040 0,886 0,042
Lab 3 0,93 0,78 0,88 0,014 0,009 0,011 1,059 0,019 0,895 0,016
Lab 4 0,85 0,71 0,80 0,011 0,016 0,011 1,071 0,023 0,897 0,025
Lab 5 0,92 0,84 0,88 0,020 0,021 0,026 1,045 0,047 0,947 0,039
Lab 6 0,89 0,63 0,84 0,018 0,050 0,011 1,059 0,025 0,754 0,054
Lab 7 0,91 0,66 0,86 0,028 0,044 0,015 1,057 0,044 0,769 0,056
Lab 8 0,87 0,75 0,85 0,013 0,017 0,009 1,041 0,028 0,890 0,021
Lab 9 0,92 0,73 0,88 0,012 0,011 0,016 1,047 0,026 0,832 0,023
Lab 10 0,92 0,88 0,88 0,026 0,020 0,014 1,045 0,021 1,000 0,035
Lab 11 0,90 0,80 0,75 0,016 0,030 0,015 1,191 0,026 1,055 0,035
Lab 12 0,96 0,80 0,86 0,005 0,028 0,013 1,119 0,021 0,932 0,034
Lab 13 0,92 0,74 0,88 0,011 0,022 0,016 1,044 0,023 0,844 0,025
Lab 14 0,95 0,81 0,88 0,011 0,021 0,021 1,084 0,025 0,920 0,028
Lab 15 0,96 0,84 0,94 0,009 0,008 0,011 1,019 0,019 0,894 0,008
Lab 16 1,077 0,027 0,814 0,026
Lab 17 0,92 0,74 0,89 0,013 0,014 0,009 1,041 0,015 0,835 0,016
Lab 18 0,92 0,78 0,86 0,011 0,017 0,031 1,068 0,042 0,903 0,023
Lab 19 0,99 0,93 0,94 0,009 0,011 0,008 1,052 0,003 0,989 0,014
Average 0,92 0,77 0,86 0,02 0,02 0,02 1,069 0,027 0,889 0,030
Sr 0,017 0,024 0,017 0,029 0,032
SR 0,037 0,079 0,050 0,048 0,082
Sr % 1,89% 3,16% 1,96% 2,70% 3,65%
SR % 4,02% 10,28% 5,80% 4,49% 9,23%
After recalculation (without lab 11)
Average 0,92 0,77 0,86 0,016 0,022 0,016 1,062 0,027 0,879 0,029
Sr 0,017 0,024 0,017 0,029 0,032
SR 0,037 0,079 0,050 0,038 0,073
Sr % 1,89% 3,16% 1,96% 2,73% 3,67%
SR % 4,02% 10,28% 5,80% 3,58% 8,30%
5.3 Drying
An overview on the drying test results is given in table 4. More detailed views on
the load performance is given in figures 13.
5.4 Energy
Determination of energy consumption is done during the cleaning tests. Relevant
values are not releative ratios as before, but the absolute energy consumption in
kWh. Figure 14 shows a graphical comparison of these. Table 3 holds the numerical
values. A list of used equipment is available in table 5.
25

5.4 Energy CECED DW Ringtest
Drying index
drying index
drying index
1,00
0,90
0,80
0,70
0,60
0,50
0,40
0,30
0,20
0,10
0,00
1,00
0,90
0,80
0,70
0,60
0,50
0,40
0,30
0,20
0,10
0,00
1,00
0,90
0,80
0,70
0,60
0,50
0,40
0,30
0,20
0,10
0,00
Drying Crockery
Ref crockery H crockery L crockery
Ref glass H glass L glass
Ref cutlery H cutlery L cutlery
Drying glass
Drying cutlery
© Uni Bonn 2003
© Uni Bonn 2003
© Uni Bonn 2003
Figure 13: Drying results by load type (corckery, glass and cutlery)
26

5.4 Energy CECED DW Ringtest
Energy [kWh]
2,00
1,90
1,80
1,70
1,60
1,50
1,40
1,30
1,20
1,10
1,00
Cleaning energy consumption
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
1,59
Energy [kWh] machine H Energy [kWh] machine L Energy [kWh] R*
Figure 14: Energy consumption during the cleaning tests
27
© Uni Bonn 2003

5.5 Verification of laboratory conditions CECED DW Ringtest
5.5 Verification of laboratory conditions
Besides the data which is gathered anyway, like temperature and air humidity,
questionnaires have been sent to the participants to collect important background
information on the laboratory equipment and testing practise.
5.5.1 Air temperature and humidity, water temperature and hardness
Generally ambient conditions have been met in all laboratories, only few anomalies
appeared occasionally. The graphs in Annex C show details on the ambient
conditions where the data is available.
5.5.2 Reference machine operation
Limits for reference machine operation are given in the standard (see EN 50242,
C.2), but often not regarded or exceeded. Especially the cleaning performance of
the reference machine is of importance, since it affects the cleaning ratio (see figure
8 for example).
5.5.3 Laboratory equipment
28

5.5 Verification of laboratory conditions CECED DW Ringtest
Laboratory equipment
Lab #
Table 5: Laboratory equipment
drying
cabinet microwave
Ref
machine
Energy
measurement
Lab 01 ULM800 (2000) HMTF750F (1996) G 595 SC, 1999 0
Lab 02 0 0 0 0
Lab 03 0 0 0 0
Lab 04 0 0 0 0
Lab 05 0 0 0 0
Lab 06
1. MEMMERT ULM
800 (2 units) / F-Nr:
F899.0064 and F-
Nr: F899.0095 and
purchased in year
1999.
1. BSH HMT 752 F / FD
7711 XN7251210 and
Miele M732 / 30242480
and BSH was
purchased in year 2000
and Miele was
purchased in 1995. 0 0
Heraeus NTU
G 595SC,
00000019,
2,7kW,
Lab 07 100/150 Siemens HF 13563 rectangular 0
Memmert ULE800, Bosch HMT 752F, NN-
Lab 08 D06064
3454BGHG, 1996 0 0
Lab 09 0 0 0 0
Memmert UM800,
IEC 61306 cl 1,
AAC1D5D10CR2A00
Lab 10 ser 895.0013 0 0 by SAIA-Burges
Memmert ULM 800, Siemens HF 13563 /
Lab 11 D06064 Nr. 800.006 MN 3414 BGSG 0 0
BOSCH, HMT752F/01 G595SC S/N
MAZZALI code FD7901 X191202090; 00/00000002..a
AMAC4BPS0000 FD7610 UO6040244; nd year of
art.n°
FD 7709 X97040576; purchase...1999
1302;1303;1304;17 FD7810 XO8010236... .....; G590SC
76 and purchased and purchased in year S/N
Lab 12 in year 1997/2000
Zanussi, temp
1998/2001
14/17152210. 0
Lab 13 control Bosch 0
Lab 14 0 0 0 0
Lab 15 0 0 0 0
Memmert ULM800 Bosch HMTF752F
f801.0033 FD7609 U96121336
Lab 16 purchased 2001 (2000) 0 0
Lab 17 Memmert ULE
800,F-Nr. 98 96
0041 und ist mit
Gitterrosten (Art.-
Nr. B02 439)
0 0 0 0
undAbstandsleisten
Waldsee LVM 219,
Lab 18 (Art.-Nr. B04 057) 0 0 Messfehler ± 0,5 %
Lab 19 0 0 0 0
29

5.6 Noise emission CECED DW Ringtest
5.6 Noise emission
Since EN 60704 sound measurement is not available in all facilities and causes
additional costs for the participant noise emission measurement has only been done
by certain laboratories. Please notice that lab 11 performed the test with freestanding
but uncovered machines. This data is kept only for sake of completeness,
it should not be compared to the other results.
Figure 15 gives an overview on the machines’ noise emissions.
max. power level db(A)
120
100
80
60
40
20
0
49,5 50,2 51,3
47,4 46,5 46,3
Maximum Sound power levels dB(A)
55,2
51
51,5 51,4 51,9 51,2
46,6
47,7
54,1
50,8
Lab 02 Lab 06 Lab 07 Lab 08 Lab09 Lab 11 Lab 12 Lab 13
L H Difference Background Noise
Figure 15: Noise emission: sound power levels compared
30
© Uni Bonn 2003
6
4
2
0
difference dB(A)
-2
-4
-6

6 Analysis
CECED DW Ringtest
Determination of the results’ repeatability (within-lab deviations) and reproducibility
(inter-lab deviations) was done according to IEC 61923:1997. Beforehands
outlier were identified using common statistical methods: the Cochran test and
Grubb’s test to identify numerical outliers (e.g. see ISO 5725-2, 7.3.2). Critical
values for both tests are taken from ISO 5725-2 (p.21-22).
The performance calculations were implemented in Microsoft Excel using the formulas
described in EN 50242 (6.7 and 7.4).
Additionally the Mandel h and k tests (IEC 61923:1997, 6.1) were applied to the
cleaning and drying indexes as well as the values of Energy consumption, though
the results were considered only to fortify the decisions made using the numerical
test methods above.
It should be noted here that the absolute values (performance averages) are not
taken into account for outlier analysis.
6.1 Cleaning outliers
Although Grubb’s test for numerical outliers indicates machine H as underperforming
outlier in lab 09, the data is kept for it not extremely lower than other and in
several cases labs show almost as low values.
The H performance in lab 05 is exceptionally high though and clearly an outlier
(see table 6 and figure 2), therefore removed for accuracy calculation.
The Cochran test (table 7) for examination of inner deviations between the runs
(affecting repeatability) does not reveal anomalies, unless absolute values instead
of the ratios would be considered.
6.2 Drying outliers
In the case of laboratory 11 both drying ratios exceed the critial value of Grubb’s
test (the ratios are far too high, see table 8), which is a clear indication that laboratory
11 is an outlier.
It should be noticed that drying indexes in Lab 19 have been too high for all machines
and have exceeded the critical values of the Grubbs test. Of course the drying
ratios are not affected and well within the allowed range, therefore laboratory 19 is
not regarded as outlier.
Within the variances of the absolute drying indexes can be observed that the drying
of the L machines varies too much in Lab 6, and several stragglers can be found.
Again, the drying performance ratios are not affected and stay well within allowed
range of Cochran’s test statistics (see table 9).
31

6.2 Drying outliers CECED DW Ringtest
Table 6: Grubb’s test for the cleaning runs
Cleaning runs Grubbs test
H performance Low performance R performance H ratio
L ratio
Max 4,460 Lab 16 4,100 Lab 05 4,480 Lab 16 1,231 Lab 05 0,984 Lab11
5,429 (**outlier) 5,475 (**outlier) 8,436 (**outlier) 5,006 **outlier 1,642
Min 3,320 Lab 09 2,990 Lab 09 3,370 Lab 07 0,973 Lab 09 0,856 Lab 15
5,889 (**outlier) 3,253 (**outlier) 3,269 (**outlier) 2,801 *straggler 1,815
crit. Val. **1% 2,968 *5% 2,681 p=19
Table 7: Cochran’s test for the cleaning runs
Cochran´ test
H perf L perf R perf H ratio L ratio
Max. 0,058 0,074 0,044 0,0035 0,0058
statistic c 0,234 0,197 0,183 0,143 0,175
Lab 01 Lab 12 Lab 05 Lab 05
(*straggler)
crit. Values **1% 0,238 n=5
*5% 0,200 p=19
Table 8: Grubb’s test for the drying runs
Drying runs Grubb's test
H performance Low performance R performance H ratio
L ratio
Max 0,990 Lab 16 0,930 Lab 05 0,940 Lab 16 1,191 Lab 11 1,055 Lab 11
4,419 (**outlier) 7,460 (**outlier) 4,913 (**outlier) 4,528 **outlier 5,595 **outlier
Min 0,850 Lab 09 0,630 Lab 09 0,750 Lab 07 1,019 Lab 15 0,754 Lab 06
4,419 (**outlier) 6,383 (**outlier) 7,175 (**outlier) 1,867 4,521 (**outlier)
crit. Val. **1% 2,968 *5% 2,681
Table 9: Cochran’s test for the drying runs
Drying runs Cochran's test
H perf L perf R perf H ratio L ratio
max 0,001 0,0025 0,0010 0,0022 0,0031
statistics 0,161 0,240 0,188 0,138 0,155
Lab 02 Lab 06 Lab 05 Lab 05 Lab 07
(**outlier)
crit. Values**1% 0,238 p=19
*5% 0,200 n=5
32

6.3 Repeatability and Reproducibility CECED DW Ringtest
Table 10: Repeatability and reproducibility of cleaning, drying and energy measurement.
Values taking into account outliers are written in parenthesis.
Repeatability Reproducibility
Cleaning High 3,22% (3,36%) 5,49% (6,66%)
Cleaning Low 4,52% 5,74%
Drying High 2,73% (2,70%) 3,58% (4,49%)
Drying Low 3,67% (3,65%) 8,30% (9,23%)
Energy cons. High 0,71% 2,39%
Energy cons. Low 1,64% 3,36%
Energy cons. Ref 0,86% 4,99%
6.3 Repeatability and Reproducibility
As shown above several values can be regarded as outliers, which affect the ringtest
reference standard repeatability and reproducibility. The calculations of tables 2
and 4 are summarized in table 10.
Concering the above the results, the following statements can be made towards
accuracy of EN 50242:A3:
1. The requirement that the reference machine shall have the lowest variability
has not been met.
33

7 Conclusion
CECED DW Ringtest
Comparing the current accuracy to those achieved in ringtest no. 3 of Cenelec TC
59X WG2 (see A), the current seem equal or slightly worse. An improvement of
accuracy cannot be clearly observed, but nevertheless is possible since this ringtest
takes into account more laboratories and as well those laboratories with fewer testing
experience. Furthermore no test before has been done with two sets of machines.
Following conclusions may be taken for results achieved under EN 50242:A3 when
measured in different laboratories:
• Measurement of cleaning performance may differ up to two classes
• Measurement of drying performance may differ up to three classes
• Measurement of energy consumption seems reasonable within one class
• Improvement and alignment of the laboratory practise is necessary
• A need to clarify certain points in the standard has been identified
• Regular ring-testing is necessary to exchange experience and align and verify
laboratory practise
Annotations The accuracy analysis does not regard possible exceedings of the
reference machine operation limits given in the standard. If this had been the case,
far more laboratories would have been removed from calculations.
34

A Results of ringtest no.3
The cleaning performance of the test appliance can be measured with
• a repeatability standard deviation* Sr of 3.5%
• a reproducibility standard deviation* SR of 4.8%.
The drying performance of the test appliance can be measured with
• a repeatability standard deviation* Sr of 5.9%
• a reproducibility standard deviation* SR of 9.5%.
CECED DW Ringtest
Regarding the absolute values measured for the water and energy consumption (the
outliers were not eliminated): the absolute values of the energy consumption can
be measured with
• a repeatability standard deviation* Sr of 2.8%
• a reproducibility standard deviation* SR of 5.8%.
th absolute values of water consumption can be measured with
• a repeatability standard deviation* Sr of 1.5%
• a reproducibility standard deviation* SR of 3.3%.
*Note: These standard deviations show only the variation of the repeatability within
one lab and the influence of different labs, they do not include the deviations caused
by different samples of dishwashers so there is a need to increase these values to
come to overall tolerances.
B Contact persons
B.1 Responsibility on behalf of CECED
Hans Beer
BSH
beer@bshg.com
B.2 Ringtest coordination and evaluation
Dr. Rainer Stamminger
Uni Bonn
stamminger@uni-bonn.de
Daniel Pozzi
Uni Bonn ringtest@uni-bonn.de
B.3 Participants
Contact to the ringtest responsibles will be made available on their permission.
35

C Cleaning and drying courses
36
CECED DW Ringtest

cleaning index
cleaning index, hardness
cleaning index. hardness
5,00
4,50
4,00
3,50
3,00
2,50
2,00
1,50
1,00
0,50
0,00
5,00
4,50
4,00
3,50
3,00
2,50
2,00
1,50
1,00
0,50
0,00
5,00
4,50
4,00
3,50
3,00
2,50
2,00
1,50
1,00
0,50
0,00
High cleaning North
1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5
Lab 05 Lab 04 Lab 07 Lab 09 Lab 14 Lab 18
H cleaning West
1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5
Lab 02 Lab 10 Lab 06 Lab 11 Lab 17 Lab 16 Lab 19
High cleaning South
1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5
Lab 01 Lab 03 Lab 13 Lab 08 Lab 12 Lab 15
Figure 16: H cleaning course by tier
37
CECED DW Ringtest
5,0
0,0
30,0
25,0
20,0
15,0
10,0
5,0
0,0
30,0
25,0
20,0
15,0
10,0
5,0
0,0
water, temp
35,0
30,0
25,0
20,0
15,0
10,0
H crockery
R crockery
H glass
R glass
H cutlery
R cutlery
H total
R total
H energy
R energy
H humidity
R humidity
H hardness
R hardness
H inlet
R inlet
H max wash
R max wash
H water
R water
H air temp
R air temp
H crockery
R crockery
H glass
R glass
H cutlery
R cutlery
H total
R total
H energy
R energy
H humidity
R humidity
H hardness
R hardness
H max wash
r max wash
H water
R water
H air temp
R air temp
H inlet
R inlet
H crockery
R crockery
H glass
R glass
H cutlery
R cutlery
H total
R total
h energy
R energy
H humidity
R humidity
H hardness
R hardness
H inlet
R inlet
H max wash
R max wash
H water
R water
H air temp
R air temp

5,00
4,50
4,00
3,50
3,00
2,50
2,00
1,50
1,00
0,50
0,00
cleaning index
cleaning index
5,00
4,50
4,00
3,50
3,00
2,50
2,00
1,50
1,00
0,50
Low cleaning North
1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5
Lab 05 Lab 04 Lab 07 Lab 09 Lab 14 Lab 18
Low cleaning West
0,00
0,0
1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5
5,00
4,50
4,00
3,50
3,00
2,50
2,00
1,50
1,00
0,50
0,00
Lab 02 Lab 10 Lab 06 Lab 11 Lab 17 Lab 16 Lab 19
Low cleaning South
1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5
Lab 01 Lab 03 Lab 13 Lab 08 Lab 12 Lab 15
Figure 17: L cleaning course by tier
38
30,0
25,0
20,0
15,0
10,0
5,0
0,0
30,0
25,0
20,0
15,0
10,0
5,0
35,0
30,0
25,0
20,0
15,0
10,0
5,0
0,0
CECED DW Ringtest
L crockery
R crockery
L glass
R glass
L cutlery
R cutlery
L total
R total
L energy
R energy
L humidity
R humidity
L hardness
R hardness
R inlet temp
L max wash
R max wash
L water
R water
L air temp
R air temp
L inlet
© Uni Bonn 2003
L crockery
R crockery
L glass
R glass
L cutlery
R cutlery
L total
R total
L energy
R energy
L humidity
R humidity
L hardness
L max wash
R max wash
L water
R water
L air temp
R air temp
R hardness
L inlet
R inlet
© Uni Bonn 2003
L crockery
R crockery
L glass
R glass
L cutlery
r cutlery
L total
R total
L energy
R energy
L air humidity
R air humidity
L hardness
R hardness
L inlet
R inlet
L max wash
R max wash
L water
r water
L air temp
R air temp
© Uni Bonn 2003

drying index, hum.%
Drying index, humidity
1,20
1,00
0,80
0,60
0,40
0,20
0,00
High drying: North
Lab 05 Lab 04 Lab 07 Lab 09 Lab 14 Lab 18
drying High West
0,00
0,0
1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5
1,20
1,00
0,80
0,60
0,40
0,20
0,00
1,20
1,00
0,80
0,60
0,40
0,20
Lab 02 Lab 10 Lab 06 Lab 11 Lab 17 Lab 16 Lab 19
drying High South
1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5
Lab 01 Lab 03 Lab 13 Lab 08 Lab 12 Lab 15
25,0
20,0
15,0
10,0
Figure 18: H drying course by tier
39
5,0
0,0
temp, hardness
CECED DW Ringtest
H crockery
R crockery
H glass
R glass
H cutlery
R cutlery
H total
R total
H humidity
R humidity
L temp
R temp
hardness mmol/l
© Uni Bonn 2003
25,0
20,0
15,0
10,0
5,0
25
20
15
10
5
0
H crockery
R crockery
H glass
R glass
H cutlery
R cutlery
H total
R total
H humidity
R humidity
H temp
R temp
H hardness
© Uni Bonn R hardness 2003
H crockery
R crockery
H glass
R glass
H cutlery
R cutlery
H total
R total
H humidity
R humidity
H temp
R temp
H hardness
© Uni Bonn R hardness 2003

drying index, hum.%
drying index, hum.%
drying index, hum.%
1,10
1,00
0,90
0,80
0,70
0,60
0,50
0,40
0,30
0,20
0,10
0,00
1,10
1,00
0,90
0,80
0,70
0,60
0,50
0,40
0,30
0,20
0,10
0,00
1,10
1,00
0,90
0,80
0,70
0,60
0,50
0,40
0,30
0,20
0,10
0,00
Low drying: North
Lab 05 Lab 04 Lab 07 Lab 09 Lab 14 Lab 18
Low drying: West
0,0
Lab 02 Lab 10 Lab 06 Lab 11 Lab 17 Lab 16 Lab 19
Low drying: South
Lab 01 Lab 03 Lab 13 Lab 08 Lab 12 Lab 15
25,0
20,0
15,0
10,0
Figure 19: L drying course by tier
40
5,0
0,0
temp, hardness
CECED DW Ringtest
L crockery
R crockery
L glass
R glass
L cutlery
R cutlery
L total
R total
L humidity
R humidity
L temp
R temp
hardness mmol/l
© Uni Bonn 2003
25,0
20,0
15,0
10,0
5,0
25
20
15
10
5
0
temp, hardness
temp, hardness
L cutlery
R cutlery
L total
R total
L humidity
R humidity
L crockery
R crockery
L temp
R temp
hardness
mmol/l
L crockery
R crockery
L glass
R glass
L cutlery
R cutlery
L total
R total
L humidity
R humidity
L temp
R temp
hardness
mmol/l

References
CECED DW Ringtest
EN 50242:A3
Electric dishwashers for household use - Test methods for measuring performance
European Comittee for Electrotechnical Standardization, Brussels 2003
CEI/IEC 61923
Household electrical appliances - Methods of measuring performance - Assessment
of repeatability and reproducibility
Technical report
International Electrical Commission, Geneva 1997
ISO 5725-2:1994(E)
Accuracy (trueness and precision) of measurement methods and results, Part 2:
Basic method for the determination of repeatability of a standard measurement
method
International Organisation for Standardisation, Geneva 1994
41