Kistler 6041 Series User manual

Instruction
Manual
7061_002-027e-09.18
Water cooled
piezoelectric
pressure sensors
Types
6041...,
6043...,
6061...,
6067...,
7061...

Instruction
Manual
7061_002-027e-09.18
Water cooled
piezoelectric
pressure sensors
Types
6041...,
6043...,
6061...,
6067...,
7061...

Page 17061_002-027e-09.18
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guished by technical innovation, precision and long life.
Information in this document is subject to change without
notice. Kistler reserves the right to change or improve its
products and make changes in the content without obliga-
tion to notify any person or organization of such changes
or improvements.
© 1999 ... 2018 Kistler Group. Kistler Group products are
protected by various intellectual property rights. For more
details visit www.kistler.com. The Kistler Group includes
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the Americas and Australia.
Kistler Group
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Switzerland
Tel. [phone]
[e-mail]
www.kistler.com
Foreword
Foreword

Water cooled piezoelectric sensors
7061_002-027e-09.18Page 2
Content
1. Introduction ...................................................................................................................................3
1.1 Disposal instructions for electronic equipment ...................................................................4
1.2 Software upgrades and updates.........................................................................................4
2. Preface..........................................................................................................................................5
2.1 Techical data and documentation .......................................................................................5
2.2 Principle of operation..........................................................................................................6
2.3 Requirements to water cooling ...........................................................................................7
2.4 Precautions for water cooling .............................................................................................7
3. Installation of the piezoelectric sensor ..........................................................................................9
3.1 General information ............................................................................................................9
3.2 Direct installation ................................................................................................................9
3.3 Installation with sleeve........................................................................................................9
3.4 Installation examples ........................................................................................................10
3.5 Machining the mounting bore ...........................................................................................11
3.6 Mounting the water hose on the cooling pipe ...................................................................11
3.7 Check points before installation........................................................................................12
4. Installing the sensor into the bore ...............................................................................................13
5. Piezoelectric sensor cable routing ..............................................................................................14
6. Setting up the measuring chain ..................................................................................................15
6.1 Connectingthepiezoelectriccabletochargeamplier ....................................................15
6.2 Selecting the sensor sensitivity ........................................................................................15
7. Dismounting and maintenance ...................................................................................................16
7.1 Dismounting......................................................................................................................16
7.2 Maintenance .....................................................................................................................16
Kistler Technical Center services...........................................................................................................19
Total pages 19

Introduction
Page 37061_002-027e-09.18
1. Introduction
Please take the time to thoroughly read this instruction
manual. It will help you with the installation, maintenance,
and use of this product.
To the extent permitted by law Kistler does not accept any
liability if this instruction manual is not followed or pro-
ducts other than those listed under Accessories are used.
Kistler offers a wide range of products for use in measu-
ring technology:
Piezoelectric sensors for measuring force, torque,
strain, pressure, acceleration, shock, vibration and
acoustic-emission
Strain gage sensor systems for measuring force and
moment
Piezoresistive pressure sensors and transmitters
Signal conditioners, indicators and calibrators
Electronic control and monitoring systems as well as
softwareforspecicmeasurementapplications
Data transmission modules (telemetry)
Kistler also develops and produces measuring solutions
fortheapplicationeldsengines,vehicles,manufacturing,
plastics and biomechanics sectors.
Our product and application brochures will provide you
with an overview of our product range. Detailed data
sheets are available for almost all products.
If you need additional help beyond what can be found
either online or in this manual, please contact Kistler‘s
extensive support organization.

Water cooled piezoelectric sensors
7061_002-027e-09.18Page 4
1.1 Disposal instructions for electronic equipment
Do not discard old electronic devices in municipal trash.
For disposal at end of life, please return this product to
an authorized local electronic waste disposal service
or contact the nearest Kistler sales ofce for return
instructions.
1.2 Software upgrades and updates
Kistler may from time to time supply upgrades or updates
for embedded software. Such upgrades or updates must
always be installed.
Kistler declines any liability whatsoever for any direct or
consequential damage caused by products running on
embedded software which has not been upgraded or up-
dated with the latest software supplied.

Preface
Page 57061_002-027e-09.18
2. Preface
Water cooled piezoelectric sensors are the most precise
cylinder pressure sensors. They are essential for per-
forming high-precision thermodynamic studies such as
assessment of the combustion curve, determination of the
friction loss and analysis of the gas exchange. The built-
in water cooling keeps the sensing element at constant
temperature (most stable sensor sensitivity regardless
of the engine operating condition) and reduces the load-
change drift (zero offset of the pressure signal) during the
measurement.
Types 6041 6061 6067 7061 6043
Fig. 1: Water-cooled cylinder pressure sensors
2.1 Techical data and documentation
Data sheets are available on www.kistler.com.

Water cooled piezoelectric sensors
7061_002-027e-09.18Page 6
2.2 Principle of operation
The sensor membrane converts the measured pressure
into a force which is applied to the piezoelectric measu-
ring element. In the piezoelectric crystal package this
force generates an electrostatic charge proportional to the
load. An electrode collects this charge and supplies it to
the sensor connector, then via the piezoelectric cable; the
chargeamplierconvertsthischargeintoanelectricvol-
tage for measurement and processing.
The piezoelectric principle is most suited for measure-
ments of fast, dynamic and quasi-static pressure changes
and thus plays a key role in engine pressure measure-
ments.
Fig. 2: Cross section of a piezoelectric water cooled
sensor

Preface
Page 77061_002-027e-09.18
2.3 Requirements to water cooling
The use of cooling system Kistler Type 2621 is highly
recommended. It is capable of supplying up to ten water
cooled piezoelectric sensors (depending on the heat load
created by the application) with the optimum quantity of
water, at the right pressure and constant temperature. This
facilitates measurements with absolute reproducibility and
best lifetime of the piezoelectric sensors.
Coolant temperature:
50 °C
Coolantowrate:
0.3 to 0.5 l/min
Coolant pressure:
1.7 ±0.2 bar
Coolant composition:
demineralized water according to VDE-Norm 0510
cooling uid additive BASF G30/G40/G48 or similar
product (do not mix with each other)
Mixing ratio: 1 part additive with 4 parts demineralized
water suitable for applications down to –9 °C
For more information refer to datasheet and instruction
manual of cooling unit Type 2621
Never connect the piezoelectric sensor to an open coo-
ling system with water from the mains supply. This water
source contains calcium and lime deposits and will ac-
cumulate inside the piezoelectric sensor –impacting the
sensitivity and even in the worst case, block the cooling
channel inside the piezoelectric sensor.
2.4 Precautions for water cooling
The water cooling system must be turned on before the
engine is started. The reason is that if the water cooling
system is turned on after the engine has been running for
a period of time, the piezoelectric sensor may be dama-
ged due to the low temperature coolant encountering the
hot piezoelectric sensor (thermal shock effect).
Do not start the water cooling system if the temperature
of the piezoelectric sensor is high.

Water cooled piezoelectric sensors
7061_002-027e-09.18Page 8
If the water cooling system fails and cannot work normally,
the engine and water cooling system should be shut down
immediately to prevent the water cooling system from
working intermittently, thus damaging the sensor. To con-
tinue using the water cooling system, stop the engine until
the temperature of the piezoelectric sensor drops to ap-
proximately the same temperature as the coolant.
During the operation of the water cooling system, it must
be ensured that the water hoses and tubes are not con-
stricted–freeowofthecoolantisessential.
Beforeusingthesensorwithoutwatercooling,emptythe
water from the sensor, ush it with demineralized water
and blow it out very carefully with compressed air. The
same procedure should be applied before storing the
sensor when not in use.

Installation of the piezoelectric sensor
Page 97061_002-027e-09.18
3. Installation of the piezoelectric sensor
3.1 General information
The accuracy of a measurement and quality of the data
are highly dependent on careful installation of the piezo-
electric pressure sensor.
Thesensorboremustbemachinedtothespeciedtole-
rances.
Thespeciedtighteningtorqueofthepiezoelectricsensor
must be observed.
3.2 Direct installation
Direct installation requires the least installation space. Of
course, a direct installation is only possible if it is not ne-
cessary to cross any water or oil galleries in the cylinder
head casting.
In the case of repeated mounting and dismounting of
the sensor, there is the risk of damaging the sealing me-
chanism and thread of the mounting bore. Typically, the
cylinder head material is softer than that of the sensor.
Beforemountingthesensorinthebore,alsotofacilitate
dismounting it at the end of the test, it is recommended
to coat thread and sealing part of the piezoelectric sen-
sor with high temperature resistant grease (for example
MOLYKOTE HSC plus or Metaux 70-81). Do not apply
any grease on the membrane.
3.3 Installation with sleeve
In the case where the cylinder can only be accessed via
an oil or cooling water gallery, a mounting sleeve is ne-
cessary to provide adequate sealing for the installation. At
the front, the sleeve is screwed and sealed with a sealing
ring at the rear, sealing is achieved using O-rings and/or
Loctite compound (Loctite 648 for shaft-hub, Loctite 290
for thread).

Water cooled piezoelectric sensors
7061_002-027e-09.18Page 10
Benetsofusingamountingsleeve:
Precise sensor bore inside the sleeve
Machining of the bore for the mounting sleeve is
simplied
The mounting sleeve has the required strength to en-
sure that the sealing part can resist wear. This allows
the sensor to be mounted and dismounted repeatedly
without restrictions
When removing the sensor, the mounting sleeve pre-
ventscoolinguidfrompassingfromleakingintocom-
bustion chamber
Disadvantages of using a mounting sleeve:
Can inuence on the cylinder head cooling perfor-
mance (depending on size and position of the sleeve
with respect to the water cooling channels)
3.4 Installation examples
Fig. 3: Left:sleevemountingwithmembraneush;
right: direct mounting with small gas channel

Installation of the piezoelectric sensor
Page 117061_002-027e-09.18
3.5 Machining the mounting bore
When preparing the sensor bore, ensure that the thread
is concentric in relation to its individual steps. The sealing
part must be completely at. Refer to the specications
and tolerances stated on the datasheet of the sensor.
All machining steps with the drill, milling cutter, reamer
and screw tap must be performed with the work held se-
curely in the same position.
3.6 Mounting the water hose on the cooling pipe
Soak the end of the rubber hose in boiling water for seve-
ral seconds – this allows expansion via heating to assist
tting,thenttherubberhoseonthecoolingpipeofthe
sensor. With this procedure it is not necessary to rotate
therubberwaterhosebackandforthwhilstttingasthis
creates a risk of loosening the cooling pipe. If a cooling
pipe becomes loose, it must be unscrewed completely
– then follow the procedure as mentioned in the chapter
"maintenance".

Water cooled piezoelectric sensors
7061_002-027e-09.18Page 12
3.7 Check points before installation
Water leakage - After connecting the rubber hoses to
the cooling pipes of the sensor, operate the cooling
system and check that there is no leakage
Piezoelectric cable - If the piezoelectric cable connec-
ted to the sensor is loose it must be retightened. Note
thatthepiezoelectriccableofsensortype6041Bisac-
cessible only after removing one of the water cooling
pipes (see chapter "maintenance")
Carefully check the piezoelectric cable for damage
over its full length, and if necessary replace it comple-
tely. The insulation resistance of sensor and piezoelec-
tric cable should be checked by connecting the insu-
lation tester at the end of the piezoelectric cable. The
minimumrequirementatroomtemperatureis10E13Ω
Sensor seal ring - The sensor seal ring must al-
ways be applied to the sensor as shown in Figure
4. If the seal ring is damaged, it should be replaced
Fig. 4: Seal ring of a shoulder sealing sensor
Mounting bore - Check the condition of the mounting
bore;itmustbemachinedtothespecieddimensions
and tolerances as described in the datasheet, and also
clean and dry prior to installation

Installing the sensor into the bore
Page 137061_002-027e-09.18
4. Installing the sensor into the bore
Feed the piezoelectric cable and both rubber hoses
through the mounting wrench, and then t the mounting
wrench on the hex of the sensor. If you are using the slot-
ted mounting wrench Type 1300A73 for sensor Type 6041,
pay attention to proper positioning of the piezoelectric
cable and rubber water hoses in the slot (otherwise
danger of compression damage). Make sure the pins
are properly engaged into the small bores of the sensor.
Before installing the sensor in the bore, the thread and
sealing part should be lubricated with high-temperature
resistant grease (for example MOLYKOTE HSC plus or
Metaux70-81).Thiswillfacilitatedismountingthesensor
from the bore post-testing.
During installation and disassembly, the piezoelectric
cable and rubber water hoses should be rotated with the
mounting wrench to avoid damage of the piezoelectric
cable and the possibility of inadvertently loosening the
cooling pipes. During use, pay attention to protect the
sensor piezoelectric cable. Do not squash, twist or pull the
piezoelectric cable.
Screw the sensor hand-tight and then use the torque
wrenchfortighteningtotherequiredvalueasspeciedin
the datasheet of the sensor.
When the sensor installation is completed, connect the
water hoses to feed and return manifolds of the water
cooling system.
Fig. 5: Assembly with water cooled sensor and moun-
ting wrench for installation

Water cooled piezoelectric sensors
7061_002-027e-09.18Page 14
5. Piezoelectric sensor cable routing
The piezoelectric cable of the sensor must be routed to
avoid other high-frequency, or power cables, as much
as possible, e.g. ignition or fuel injection system cabling,
dynamometer or motor power cables. If this cannot be
avoided, the piezoelectric cables should be kept perpen-
dicular to the high-frequency signal lines to reduce signal
interference.
There must be no mechanical tension on the piezoelec-
tric cable. It is absolutely essential to avoid deformation
caused by sharp bends. During use, pay attention to pro-
tect the piezoelectric cable: do not squash, twist or pull
it. Ensure the cleanliness of the piezoelectric cable con-
nector. Do not allow water, oil, dust, or other dirt in the
vicinity of the cable interfaces. If the piezoelectric con-
nector becomes contaminated during use, use an elec-
tronic cleaning spray to clean it. Use the cap to cover and
protect the piezoelectric connector when the piezoelectric
sensor is not in use.

Setting up the measuring chain
Page 157061_002-027e-09.18
6. Setting up the measuring chain
6.1 Connecting the piezo electric cable to charge amplier
Fig. 6: Basicarrangementofameasuringchain
Piezoelectric sensor cable, adapter, and piezoelectric ex-
tension cable should be connected before connecting its
endtotheinputsocketofthechargeamplier.
Makesurethechargeamplierisnotinmeasuringmode
when connecting the piezoelectric sensor cable to the
charge amplier input. This avoids potential damage to
sensitive electronic input circuitry.
The length of piezoelectric cables between sensor and
charge amplier should not exceed 10 m. Interference
from extraneous voltages and ground loop issues at the
test cell can be avoided, or reduced, by using a short pie-
zoelectriccableandpositioningthechargeamplierclose
to the piezoelectric sensor.
6.2 Selecting the sensor sensitivity
Since Kistler water cooled sensors can be used with wa-
ter cooling or uncooled, the sensitivity at 50 °C should be
used if water cooling is used, and the sensitivity at 250 °C
should be used in the case of uncooled operation.
Operation with water cooling is recommended to achieve
the highest accuracy of the pressure measurement (most
stable sensor sensitivity regardless of the engine opera-
ting condition, no load change drift).

Water cooled piezoelectric sensors
7061_002-027e-09.18Page 16
7. Dismounting and maintenance
7.1 Dismounting
Allow the cylinder head to cool down before removing the
sensor from the mounting bore. Dismount in reverse order
than installation:
Switch off the water cooling system
Disconnect the water hoses of the sensor from feed
and return manifold
Disconnect the piezoelectric sensor cable from the
chargeamplier/fromtheextensioncable
Feed the piezoelectric sensor cable and both rubber
hoses through the mounting wrench, carefully slide
it to the sensor, and then t the mounting wrench
on the hex of the sensor. If you are using the slotted
mounting wrench Type 1300A73 for sensor Type 6041,
pay attention to properly position piezoelectric cable
and both rubber water hoses in the slot (otherwise
danger of squeezing). Make sure the pins are properly
engaged into the small bores of the sensor
Unscrew the sensor from the bore
7.2 Maintenance
Piezoelectric pressure sensors are precision instruments;
theywilldelivermeasurementsinthespeciedaccuracy
range only if they are handled with care. Special attention
is required for the front part of the sensor – the membrane
and sealing area must always be protected against me-
chanical damage.
Do not tap impact or shock the front surface of the sensor
with metal or any other objects – this will help to avoid
damage to the membrane.
Visual inspection - Sensor, piezoelectric cable and
cooling pipes should be carefully inspected for anoma-
lies (damage, soot deposits, overheating due to com-
bustion gas leakage)

Dismounting and maintenance
Page 177061_002-027e-09.18
Cleaning - After the sensor is disassembled from the
engine, combustion deposits may be cleaned with a
soft brush and iso-propanol (NEU-TRI E). The front
part of the sensor (membrane) cannot be cleaned
using mechanical means such as brushing, sand blas-
ting, grinding, etc. as this will irreparably damage the
membrane and thus the sensor
Visual inspection - After cleaning, see above
Insulation check - The insulation resistance of the
sensor with piezoelectric cable should be checked by
connecting the insulation tester Type 5493 at the end
of the piezoelectric cable. The requirement at room
temperature is 10E13 Ω. If the value is too low, all
piezoelectric connectors should be disconnected and
the insulators cleaned with electronic cleaning spray
Kistler Type 1003 or a similar product. Do not touch the
connectorinsulatorwithbarengersanddonotblowit
out with shop compressed air
Pressure calibration - Recalibration is recommended
every 200 hours of operation or after each disassembly
of the sensor from the cylinder head
Exchange of components - It is possible to replace
the sealing ring, the piezoelectric cable, and the coo-
ling pipes. Material numbers are listed in the datas-
heet of the sensor. The replacement of the sealing ring
should be done by Kistler
Removing the cooling pipes Types 1225,
1225A1/A2/A5
Necessary material
-Hot-air blower with variable temperature
-Open ended wrench 3 mm AF
-Solvent iso-propanol or a similar product
Procedure:
-Remove the rubber hose from the cooling pipe
-Locally heat by hot-air blower the contact area of the
cooling pipe with the sensor body (max. air temp.
200 °C). Do not expose the piezoelectric cable to
the hot air (risk of overheating)
-Simultaneously unscrew the cooling pipe with the
open ended wrench 3 mm AF
-With the means of a small brush, clean the thread
M3x0.35 of the cooling pipe with iso-propanol or a
similar product
-Clean the M3x0.35 bores on the sensor: there should
not be any Loctite residue left in the cooling channel.
To achieve this, wash out the bore with NEU-TRI E
or a similar product using a small brush. Gently blow
out the individual bores using compressed air