Gaggenau ED 220/221 Product guide

Operating and assembly instructions
ED 220/221
ED 230/231
Built-in steam oven

ED 220/221
ED 230/231
1
Preface
1. Important notes Page 3-4
1.1 For your safety Page 3
1.2 About use Page 4
2. Appliance and accessories Page 5-6
2.1 Appliance description Page 5
2.2 Display Page 5
2.3 Accessories / special accessories Page 6
3. Operating for the first time Page 7-10
3.1 Important notes Page 7
3.2 Calibration Page 7-8
3.3 What to do, when ... Page 8
3.4 Determining water hardness Page 9
3.5 Entering the water hardness Page 10
4. Operation Page 11-17
4.1 Switching on and off Page 11
4.2 Control knobs Page 11
4.3 Operating modes Page 12
4.4 Operating the timer Page 13-17
5. Special functions Page 18-23
5.1 Child lock Page 18
5.2 Options menu Page 19
5.3 Core temperature sensor Page 20-21
5.4 Steaming Page 22
5.5 Condensing Page 22
5.6 Display of the current cooking compartment
temperature Page 23
5.7 Power failure protection Page 23
5.8 Holiday protection Page 23
5.9 Cleaning aid Page 23
6. Further uses Page 24-25
7. Cooking table, Baking table Page 26-30
8. Tips and tricks Page 31
9. Cleaning and care Page 32-35
9.1 Manual cleaning Page 32
9.2 Cleaning the side plate Page 33
9.3 Cleaning aid Page 34-35
10. Maintenance Page 36-39
10.1 General Page 36
10.2 Lamp replacement Page 36
10.3 Descaling Page 37
10.4 Dismantling the front window Page 38
10.5 Remedying small malfunctions yourself Page 39
11. Assembly instructions Page 40-44
11.1 Technical data Page 40
11.2 Installation notes Page 40
11.3 Installation Page 41-44

2
Preface
With your steam oven you can experience
modern professional cooking technology in
your own household.
The steam oven offers the following advantages:
– Cooking with steam allows gentle preparation.
The valuable substances contained in the
foodstuffs you prepare are retained almost
completely.
– Diverse meals can be prepared without any
transfer of taste.
– Thanks to a special combined steaming
method, foodstuffs are neither dried out nor
drained of their goodness.
– Gently re-heating up food is possible, and
prepared meals retain their natural
appearance.
To ensure that you will be able to use this
appliance in all its diversity, read through
the operating and assembly instructions
conscientiously before operating it for the first
time. The instructions contain important notes on
use, installation and maintenance of
the appliance.
On the following pages you will find important
notes on safety and operation. These notes will
serve to ensure your personal safety and the
lasting value of your appliance.
The chapters entitled “Structure and operating
principle” and “Operation” tell you all about
what your appliance can do and how you operate
it.
The chapter entitled “Cleaning and care” will
make sure that your appliance will stay operable
and beautiful for a long time.
We have also compiled some “Tips and tricks”
for your.
And now we wish you lots of fun with your
steam oven.
Fig. 1

3
1. Important notes
1.1 For your safety
You must not operate the appliance if it is damaged.
The appliance must only be connected by an
authorised specialist, paying attention to
the relevant regulations of the power supply
companies and the regional construction
regulations.
Observe the assembly instructions!
Caution: Fire risk! Do not store any combustible
objects in your appliance. When operating the
appliance, only ever leave the inner parts inside the
cooking compartment that you actually need.
As the user, you yourself are responsible for
maintenance and proper use in the household.
Only ever operate the appliance under supervision.
Disconnect the unit from the water mains when it is
not in operation.
Caution! The appliance gets hot during operation.
Keep children away!
Caution! There is a risk of injuries if the door is not
closed properly. You could jam and crush your
fingers and hands.
Caution! Steam may billow out when you open the
door. If there is steam in the oven, do not reach in
with your hands! Risk of burns!
Caution! When removing the cooking insert hot
water may drip from the oven top. Risk of
scalding! Be careful when removing the cooking
insert as hot liquid might spill. Use heat resistant
oven gloves.
Leads of other electrical appliances that are used
in the proximity of the cooker must not be jammed
in by the hot oven door.
Do not clean the appliance with a steam cleaning
apparatus or with water pressure – risk of short-
circuits!
Disconnect the appliance from the water and
electricity mains. Switch off the corresponding fuse
and turn off the tap.
Caution! For technical reasons the lamp cover
cannot be removed. Lamp must only be replaced
by Gaggenau after-sales service.
Repairs may only be carried out by authorised
electricians.
Note: The appliance must not be connected to the
hot water supply.
No warranty claims can be lodged for any
damage resulting from failure to observe these
instructions.
Technical modifications reserved.

4
1.2 About use
The appliance is intended solely for use in the
household and must not be put to any other uses.
Use the appliance to prepare meals only. It must not
be used to heat up the room in which it is installed.
Only ever use the included cooking inserts or
order the special accessories.
Do not place any items in the oven compartment
that might rust. Rusty accessories will lead to further
rusting in the oven compartment!
Do not use any silver tableware in the cooking
compartment.
The cooking compartment may become
discoloured during prolonged operation. This does
not have a detrimental influence on operability of
the appliance.
Operation is only possible when the door is closed,
otherwise there is a risk that water will spray out of
the appliance or that hot steam will come out.
The steam oven uses unpressurized steam,
therefore the door can be opened at any time
during cooking. To prevent extreme steam from
escaping when you open the door, you can
condense beforehand. Water may drip when
opening the door.
Steam may escape during operation and when
opening the door.
The (Heating) symbol in the control panel goes
off as soon as the required temperature has been
reached.
Turn the “Temperature” control knob (right control
knob) to the 0 position after use.
In the event of malfunctions, first of all check
the household fuses. If the problem has nothing to
do with the power or water supply, please contact
your specialist dealer or your local Gaggenau after-
sales service.
The door window may fog up at all moisture levels
(above all at the 100 % moisture level).
It is possible that moisture remains in the oven
interior after use at certain moisture levels. Wipe
the oven interior dry with a soft cloth after use.
Operating noise may occur in all operating modes.
Opening and closing of the air flap causes clicking
noise.
The appliance rinses automatically when switched
on if it has not been in operation for a prolonged
period of time or after a prolonged power failure
(several hours). This removes water that is left over
in the pipes.
The food being cooked must not come into contact
with the sides or the grease filter.
At set temperatures below 65°C, the light is
switched off after a few seconds to ensure that the
halogen lamp will not additionally heat
up the oven compartment. This ensures more
precise temperature coordination. The light in the
oven compartment is switched on again for a few
seconds if you turn one of the two control knobs or
if you press a key.
Calibration
(automatic boiling point-adjustment):
The boiling point of water depends on the baro-
metric pressure. The barometric pressure changes
with the altitude of the place where the appliance is
installed. During self-adjustment, the appliance
adapts itself to the pressure conditions prevailing at
the appliance’s location.
The appliance cannot be operated if it has not
been calibrated!
The appliance features a descaling display.
When it flashes, this is an indication that the
appliance must be descaled. Before commencing
operation, you must enter the water hardness in
your household on the appliance.

2.1 Appliance description
2.2 Display
1Grease filter
2Air flap
3Slide-in grills
4“Temperature” control knob
5“Moisture level” control knob
6Core temperature sensor
7Base strainer with siphon trap
8Side plate
9Display
10 Timer key
11 Core temperature sensor key
12 Plus key
13 Minus key
14 Temperature / Moisture level display
15 Time display
16 Steaming / condensing key
17 Confirmation key
18 “Child lock" symbol (symbol flashes)
“Show room mode" symbol (symbol lights constantly)
19 “Duration, end" symbol
20 “Short timer" symbol
21 “Cooking time" symbol
22 “Core temperature sensor" symbol
23 “Water connection" symbol
24 “Heating" symbol
25 “Steaming / condensing" symbol
26 “Descaling" symbol
27 “Keep door closed" symbol (during calibration)
28 “Start calibration" symbol
29 “Steaming" symbol
30 “Hot air" symbol
31 “Cleaning aid" symbol
5
2. Appliance and accessories
Fig. 2 98 7 6 54
12 3
Fig. 3
10 11 12
17 16 15 14 13
Fig. 4
18 19 20 21 22 23 24 25 26 27
29 30 31
28

2.3 Accessories / special accessories
As standard, the appliance comes with the
following accessories:
– Stainless steel cooking insert GN 2/3,
unperforated, 40 mm deep (Fig. 5)
– Stainless steel cooking insert GN 2/3,
perforated, 40 mm deep (Fig. 6)
– Wire grill (Fig. 7)
– Water connection pipe (3 m)
– Waste water pipe (3 m)
You can order the following special accessories:
– DR 220-010: Pressure reducer, connection
accessory for water pressure
6-10 bar
– GZ 010-011: Extension pipes for water
connections
– WF 040-020: Brita descaling system (filter head
and filter cartridge). If the hardness
of the water exceeds 9 ° (English
water hardness), you must install a
descaling system before the
appliance.
– WF 040-021: Set of 3 filter cartridges
– KB 220-114: Stainless steel cooking insert
GN 1/3, unperforated, 40 mm deep
– KB 220-124: Stainless steel cooking insert
GN 1/3, perforated, 40 mm deep
6
Fig. 5
Fig. 6
Fig. 7

3.1 Important notes
Before operating the appliance for the first time,
please pay attention to the following notes:
Read through these instructions attentively before
operating the appliance for the first time.
Remove the packaging from the appliance and
dispose of it properly.
Pay attention to the fact that there are accessories
in the base of the packaging.
Keep packaging elements away from children.
Thoroughly clean the appliance and accessories
before using them for the first time. This will
eliminate any “newness” smells and soiling (see
Chapter 9).
3.2 Calibration
The boiling point of water depends on the
barometric pressure at mean sea level.
During calibration, the appliance is adjusted to the
pressure conditions prevailing at the altitude where
the appliance is installed.
Recalibrate the appliance manually if you should
move home to a different altitude (see chapter
entitled “Options menu” on Page 19).
Every appliance is subjected to a thorough check
before it arrives in your home. It is therefore
possible that there is still water in the appliance.
Before operating the appliance for the first time,
make sure that the water connection is properly
secured.
When you operate the appliance for the first time,
the suggested time 8:00 appears on the display.
You can now choose the required time of day by
pressing the +and –keys. Press the
(Confirmation) key to confirm the entered value.
3. Operating for the first time
7
Important:
The calibration process cannot be interrupted.
Should the calibration process be interrupted by
opening the door or switching off the appliance,
the steam oven will not function. The appliance
will automatically start calibration until the
operation has been completed.
Recalibration is not necessary after a power
failure.

3.3 What to do, when ...
Proceed as follows:
– Install the appliance at the required location (see
assembly instructions).
– Remove all loose parts from the oven
compartment (baking tray etc.).
– Close the oven door.
– Open the water tap.
– Calibration starts automatically as soon as you
turn the “Temperature” control knob to any
temperature. The symbols “Duration”, “Keep door
closed", “00:15 h" and “CAL”for calibration
appear in the display. Calibration takes around
15 minutes. The elapsing time appears in the
display.
Note: do not open the oven door during
calibration.
– An audible signal sounds after completion of
calibration. “--:--” appears on the display.
– Turn the “Temperature” control knob back to the
0 position. The appliance is now ready for
operation.
8
Fig. 8
Fig. 9
The display repeatedly flashes the The appliance receives no water. Turn the water connection on. Check
symbol (water connection). that the pipe is correctly connected and free from bends. Turn the
“Temperature” control knob to 0 and then to the required temperature.
The Rsymbol appears on the display. The appliance has not been calibrated. Switch the appliance on,
the calibration process starts automatically.
The symbol appears on the display. The appliance is in show room mode without heating function.
The appliance does not calibrate or Disconnect the appliance from power supply for a few seconds
heat up, although the heating symbol (by switching off the fuse), then within 3 minutes press +key
appears on the display. and keep pressed and turn “Temperature” control knob to any
temperature (not light!).
The symbol flashes on the display. The child lock is operating (see page 18).
The CAL and 40 °C symbol flash The temperature in the oven is above 40°C. Therefore the calibration
alternating on the display. cannot take place. The actual temperature appears on the left of
the display. The appliance automatically cools the oven below
40 °C and re-starts the calibration.
F 61 or F 62 lights on the display. Check the power and water supply. If these are functioning
correctly call the Gaggenau after-sales service.

3.4 Determining water hardness
Water hardness range 4 has been pre-entered on
the appliance. If the hardness of the water in your
household should deviate from this value, the
correct water hardness range (between 1
and 4) must be entered before commencing
operation of the appliance. You can find out
the hardness of the water in your household either
by consulting your waterworks or by using the
included test strip.
– Run water from the tap for about 20 seconds to
drain off stale water.
– Fill a glass with tap water and briefly (no more
than 1 second) dip the test strip into the water,
making sure that all test points are wetted.
– Remove the strip from the water and shake off any
surplus water drops.
– You can read off the result after one minute.
– If your water contains lime, one or more of the test
areas is/are of a reddish colour and the others
stay light or greenish. The number of light (green)
areas defines the right water hardness range
setting on the appliance.
The test set must be used even if a water descaling
system is already installed in your household
because, depending on the descaling method, not
all scale-forming ions are removed.
Please also note that different designations are
used outside Germany to describe the hardness of
water.
Water hardness range 12 3 4
American hardness 1-7° 7-14° 14-21° >21°
French hardness 1-12° 12-25° 25-37° >37°
British hardness 1-9° 9-18° 18-26° >26°
Russian hardness 1-50° 50-100° 100-150° >150°
9
Number of light Water hardness Water
(green) areas on (German hardness) hardness
the test strip range
3 or more 1-7° 1
27-14° 2
114-21° 3
None >21° 4

3.5 Entering the water hardness
If the hardness of the water in your household
deviates from the value that is set at the works
(water hardness range 4), you must enter the
right water hardness in the options menu for
commencing operation of the appliance.
Proceed as follows:
– Turn the two control knobs to the topmost
position.
– Press the (Confirmation) key and keep it
pressed.
– Turn the “Moisture level” knob to the right.
– Release the (Confirmation) key.
– The various options appear on the display. Turn
the “Moisture level” control knob to the right to
the descaling position.
– With the + and – keys, set the water hardness
(between 1 and 4) (Fig. 11).
– Press the (Confirmation) key.
– To quit the options menu, turn the “Moisture”
control knob back up or turn the “Temperature”
control knob.
10
Fig. 11
End
Options menu
Time display
24h / 12h (AM/PM)
Descaling
Start
Calibration
Temperature
display in
°C / °F
Time display
ON/OFF
(only if appliance is switched off)
0
Fig. 10

11
4.1 Switching on and off
Switching on
Switching off
4.2 Control knobs
Switching on
– Turn the “Temperature” control knob by one
latching position to the right (Fig. 12).
The lighting goes on:
– Turn the “Moisture level” control knob to the
moisture level you require.
– Turn the “Temperature” knob to the temperature
you require.
When you turn the “Temperature” knob one latching
position to the left, the suggested temperature for
the chosen moisture level appears on the display.
100 % – 100 °C
80 % – 120 °C
60 % – 120 °C
30 % – 165 °C
0 % – 165 °C
When the “Moisture” control knob is turned, the
moisture is displayed for a few seconds.
Switching off:
To switch off, turn the “Temperature” knob to the
0 position (Fig. 13).
The steam oven lighting goes off.
It is possible that moisture remains in the oven
interior after use at certain moisture levels. Wipe
the oven interior dry with a soft cloth after use.
“Temperature” control knob:
The temperature can be set between 30 and
230 °C.
“Moisture” control knob:
You can select the following moisture levels:
100 %, 80 %, 60 %, 30 % und 0 %
4. Operation
Off
Cleaning assistance
Suggested
temperature
Moisture
control knob
Temperature
control knob
Fig. 12
Fig. 13
Fig. 14
The appliance rinses automatically when switched
on, if it has not been in operation for some days.
This removes water that is left over in the pipes
and will take no longer than 1 minute.

12
4.3 Operating modes
Moisture Temperature Display Particularly Principle Remarks
suitable for...
100% 150 - 230 °C Bread Steam baking:
poultry, The high moisture prevents the food from drying out.
puff pastry Thanks to the high temperature, the surface become
crispy brown all-round.
100% 100 °C Vegetables, Steaming: You can use several
side dishes, The food is completely surrounded by steam. cooking inserts at
blanching, Steaming is a very gently method with which the food the same time.
sterilising, is not deprived of its goodness and retains its natural
juice extraction colour.
100% 120 °C Potatoes, Fast steaming:
pulses and beans The higher temperature accelerates steaming.
Not suitable for sensitive foodstuffs.
100% 80 - 90 °C Fish Low-temperature steaming:
The air in the cooking compartment is saturated with
steam. The heat is transferred without any drying out
whatever. Protein leaking is avoided by the lower
temperature.
80% 30 - 45 °C Yeast dough, Fermenting, rising: Light goes off after
60% sour dough mixture, Thanks to the moisture, the heat is distributed a few seconds.
Yoghurt particularly evenly. The surfaces of doughs do not
dry out so much.
80% 150 - 230 °C Casserole dishes, Combined steaming:
60% gratin
middle way between steam baking and hot air
roast operation makes it possible to achieve the optimum
cooking climate for every food.
60% 120 °C Plated dishes Reheating: Meals can be heated
160 °C cooked food can be reheated gently. Thanks to the directly on the plate.
supply of steam, the food is not dried out.
Reheat food served on plates at 120 °C and baked
items at 160 °C.
80 % 45 - 50 °C Frozen foods Defrost
30% 150 - 230 °C Yeast pastry In this mode of operation, the cooking compartment
is sealed hermetically. The remaining moisture
prevents the drying effect of conventional hot air.
30% 70 - 80 °C Roast beef, Low-temperature cooking:
leg of lamb briefly seared meat can mature slowly and gently
over a long cooking time.
0% 150 - 230 °C Fruit cake Hot air: In the steam oven
the cooking compartment is ventilated and vented
you can only bake
through an opening so that the moisture produced on one level. Use the
can be dissipated. This is particularly advantageous second level from
for baked items that have to give off moisture during bottom.
the baking process.
100% 60 °C Cleaning aid:
The cleaning aid makes it possible to loosen
soiling with steam.

4.4 Operating the timer
The required moisture level and temperature can
be set before and after time programming by
turning the “Temperature” or “moisture level” knob.
As long as one or several symbol(s) in the display
flash(es), no input is possible and no value is pro-
grammed or an invalid value has been programmed.
All time values are entered by means of the
(timer), +, – and (Confirmation) keys. Every
input triggers an audible and a visible signal.
If you select a program (e.g. end), but you do not
enter a value, the current time will appear on the
display after 20 seconds.
An entered value (e.g. duration programming) must
be confirmed within 20 seconds (Confirmation)
key. Entered values are not stored if they are not
confirmed.
Press the (Confirmation) key if you wish to
confirm a value during programming.
If you press any other key instead, the entered
value will not be stored and will disappear.
You can query set values by pressing the
(timer) key. The value appears on the display for
around 10 seconds. During this time, you can
modify the value by pressing the + or – key and you
can confirm it by pressing the (Confirmation)
key.
Press the + and – keys at the same time if you wish
to clear a value.
If you have already programmed a time value once
(e.g. a duration) on the appliance, this previously
programmed value will be proposed to you when
programming a value again.
The longer you press the + or – key when
programming a time, the faster the time elapses on
the display.
After completion of time programming, the
corresponding symbol flashes on the display. For
example, if you have programmed an end time, the
(End time) symbol will flash. An audible signal is
also sounded. Heating is deactivated and the oven
lighting goes off. You can restart the previously
selected mode by pressing any key on the display.
You end the baking process by turning the
“Temperature" knob to 0.
During a time programming it is possible at any
time to turn the “Temperature” control knob back
to 0. The steam oven will then no longer heat. The
previously programmed value is retained. An
audible signal sounds after the entered time has
elapsed.
Every alarm goes off after 3 minutes.
Note: all time programming functions can be
programmed simultaneously.
Note: If the time is not displayed exactly on the
timer, this may not be due to a technical defect. The
mains frequency of the public power supply is the
time base for the timers. In Europe, this is a
standard frequency of 50 Hz (Hertz). As far as this
point is concerned, power supply networks that are
fed from power stations in eastern Europe fluctuate.
This is why an incorrect time may be displayed.
This discrepancy has no influence on the functions
and program sequences of the appliance.
13

14
Setting the time of day
Proceed as follows:
– Press the (Timer) key 3 times. The (Time
unit) symbol flashes on the display.
The time display shows the currently set time
of day (Fig. 15).
– You can select the required time by pressing
the +or –key.
– Press the (Confirmation) key to confirm the
entered value. An audible signal is sounded.
Fig. 15
After first installation or a power failure lasting
several hours, 08:00 and the time unit symbol will
flash in the display. You can set the current time by
pressing the +and –keys. 08:00 will be stored as
the time of day if you turn one of the control knobs.

Short time
You can program a period of time with the short
time function without automatic activation or
deactivation. You can use this mode of operation
even when the appliance is switched off as an egg
timer, for example. The range that can be set is
between ten seconds (00:10) and 23.59 hours
(23:59)
Proceed as follows:
– Press the +key. The short time symbol flashes
(Fig. 16).
– The entered value appears on the display, which
you can modify by pressing the +or –key. The
time unit symbol lights up.
– Press the (Confirmation) key to confirm the
entered value.
– The elapsing time is displayed.
Note: if nothing is entered for 5 seconds, the short
time starts even if the key (Confirmation) is not
pressed.
Once the short time has elapsed, an audible signal
sounds and the (Short time) symbol flashes on
the display. The signal goes off when you press any
key. The short time reminder can be switched off at
any time by pressing the +and –minus keys at the
same time.
Elapsing timer
Proceed as follows:
– Press the –key (Fig. 17).
– The time, beginning at 00:00, is displayed
(maximum display: value 12 hours).
Thus, you can continuously display the elapsed
cooking time without programming automatic
deactivation.
When you press the –key again, the time is
switched off.
15
The last programmed value is proposed to you
every other time you program a short time.
Fig. 16
Fig. 17

16
Programming a duration
The appliance is operated for a specific period of
time. The range that can be set is between one
minute (00:01) and 23 hours and 59 minutes (23:59).
Proceed as follows:
– Press the (Timer) key once. The (Duration)
symbol and the (Cooking time) symbol flash on
the display. Dashes appear on the display (i.e. no
value programmed).
– Press the +or the –key to set the required
duration.
– Press the (Confirmation) key to confirm the set
value. An audible signal is sounded. The
(Cooking time) symbol lights up on the display.
– A signal is sounded after the programmed
duration has elapsed. At the same time, the steam
oven switches off automatically.
– By pressing any key, you can switch off the signal
and heating will start again. Turn the temperature
selector switch to 0 to end the operation.
Clearing incorrectly programmed values:
– Press the (Timer) key once.
– Press the +and – keys at the same time.
An audible signal is sounded.
The end time is displayed automatically if you
press the (Timer) key twice.
Every other time you program a duration, the value
programmed last is proposed to you when you
press the +key.
Fig. 18

17
Programming a switch-off time
The appliance switches off automatically at a time
that you have chosen. The starting point is the time
of day set on the appliance.
Proceed as follows:
– Press the (Timer) key twice. The (End) and
(Cooking time) symbols flash.
– Press the +or –key to set the required time. You
can choose any switch-off time within a period of
24 hours.
– Press the (Confirmation) key to confirm the
entered value. An audible signal is sounded. The
(Cooking time) symbol lights up on the display.
After the set time has elapsed, the (Cooking
time) symbol flashes and an audible signal is
sounded.
By pressing any key, you can switch off the signal
and heating will start again. Turn the temperature
selector switch to 0 to end the operation.
Programming a duration and an off time
This mode enables you to start and end baking and
cooking in your absence.
Proceed as follows:
– Enter a required duration (see page 16).
– Press the (Confirmation) key.
– Enter the required switch-off time (see above).
– Press the (Confirmation) key.
The automatic mode becomes active as soon as
the switch-off time is programmed and you have
pressed the (Confirmation) key.
Fig. 19
Note: the time of day that is set on the appliance
is the starting point for programming the switch-off
time.
You can query the entered value by pressing the
(Timer) key twice.

5. Special functions
18
5.1 Child lock
The child lock prevents inadvertent activation of the
steam oven.
Proceed as follows:
Switching on:
– Turn the “Temperature” control knob to the right
to any temperature position (not light).
– Press the (Confirmation) key and keep it
pressed.
– Turn the “Temperature” control knob to the 0
position (Fig. 20).
The (Child lock) symbol on the display flashes.
Switching off:
– Press the (Confirmation) key and keep it
pressed.
– Turn the “Temperature” control knob to the right
to any temperature position (not light).
– Release the (Confirmation) key.
– Turn the “Temperature” control knob to the 0
position (Fig. 21).
The (Child lock) symbol on the display goes off.
Fig. 20
Fig. 21