HBM U3 User manual

A2113-2.0 en/de/fr
Force transducer
Kraftaufnehmer
Capteur de force
U3
Mounting Instructions
Montageanleitung
Notice de montage

English Page 3 - 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deutsch Seite 21 - 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Français Page 39 - 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Contents Page
English
Safety instructions 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 Scope of supply 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2 Application information 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3 Structure and mode of operation 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1 Measuring element 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Housing 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4 Conditions on site 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.1 Ambient temperature 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2 Moisture 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3 Deposits 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 Mechanical installation 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1 Important measures for installation 10. . . . . . . . . . . . . . . . . . . . . . . . .
5.2 General installation guidelines 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3 Installation for tensile loading/compressive loading 12. . . . . . . . . . .
5.3.1 Installation without adapter 12. . . . . . . . . . . . . . . . . . . . . . . . . .
5.3.2 Installation with adapter and knuckle eye 13. . . . . . . . . . . . . .
5.3.3 Installation with two knuckle eyes 14. . . . . . . . . . . . . . . . . . . .
6 Electrical connection 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.1 Instructions for cabling 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7 Specifications (VDI/VDE2638) 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8 Dimensions 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Safety instructions
Use in accordance with the regulations
Force transducers in the U3 range are designed for force measurements on
test benches/in press‐fit devices/test devices/pressing. Use for any additional
purpose shall be deemed to be not in accordance with the regulations.
In the interests of safety, the transducer should only be operated as described
in the Mounting Instructions. It is also essential to observe the appropriate
legal and safety regulations for the application concerned during use. The
same applies to the use of accessories.
The transducer is not a safety element within the meaning of its use as inten
ded. Proper and safe operation of this transducer requires proper transporta
tion, correct storage, assembly and mounting and careful operation and main
tenance.
General dangers due to non‐observance of the safety instructions
The U3 force transducer corresponds to the state of the art and is fail‐safe.
The transducers can give rise to residual dangers if they are inappropriately
installed and operated by untrained personnel.
Everyone involved with the installation, commissioning, maintenance or repair
of a force transducer must have read and understood the Mounting Instruc
tions and in particular the technical safety instructions.
Residual dangers
The scope of supply and performance of the transducer covers only a small
area of force measurement technique. In addition, equipment planners,
installers and operators should plan, implement and respond to the safety
engineering considerations of force measurement technique in such a way as
to minimise residual dangers. Prevailing regulations must be complied with at
all times. There must be reference to the residual dangers connected with
force measurement technique.

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In these mounting instructions residual dangers are pointed out using the
following symbols:
Symbol: WARNING
Meaning: Dangerous situation
Warns of a potentially dangerous situation in which failure to comply with
safety requirements can lead to death or serious physical injury.
Symbol: CAUTION
Meaning: Possibly dangerous situation
Warns of a potentially dangerous situation in which failure to comply with
safety requirements could lead to damage to property, slight or moderate
physical injury.
Symbol: NOTE
Refers to the fact that important information is being given about the product
or its use.
Symbol:
Meaning: CE mark
The CE mark signals a guarantee by the manufacturer that his product meets
the requirements of the relevant EC directives (the declaration of conformity is
available at http://www.hbm.com/HBMdoc).
Symbol:
Meaning: Statutory marking requirements for waste disposal
National and local regulations regarding the protection of the environment and
recycling of raw materials require old equipment to be separated from regular
domestic waste for disposal.
For more detailed information on disposal, please contact the local authorities
or the dealer from whom you purchased the product.

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Conversions and modifications
The transducer must not be modified from the design or safety engineering
point of view except with our express agreement. Any modification shall
exclude all liability on our part for any damage resulting therefrom. Mounting
and removing the adapter in accordance with Chapter 5 excluded.
Qualified personnel
This instrument is only to be installed by qualified personnel strictly in
accordance with the technical data and with the safety rules and regulations
which follow. It is also essential to observe the appropriate legal and safety
regulations for the application concerned. The same applies to the use of
accessories.
Qualified personnel means persons entrusted with the installation, fitting,
commissioning and operation of the product who possess the appropriate
qualifications for their function.
Conditions on site
Protect the transducer from damp and weather influences such as rain, snow,
etc.
Maintenance
The U3 force transducer is maintenance free.
Accident prevention
Although the specified nominal force in the destructive range is several times
the full scale value, the relevant accident prevention regulations from the
trade associations must be taken into consideration.

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1 Scope of supply
•1 U3 force transducer
•1 U3 Operating Manual
Accessories (not included in the scope of supply):
•'complete adapter' for knuckle eye mounting
0.5-10 kN: Adapter with four M5x12 and four M5x16 screws
Order no. 2-9289.1956
20 kN: Adapter with four M10x25 and four M10x30 screws
Order no. 2-9289.1957
50 kN: Adapter with eight M10x25 and eight M10x30 screws
Order no. 2-9289.1958
100 kN: Adapter with eight M10x25 and eight M10x30 screws each
Property class 12.9. galvanized Order no. 2-9289.2280
•Knuckle eye ZGUW for 0.5-10 kNOrder no. 1-U2A/1 t/ZGUW
20 kN Order no. 1-U2A/2 t/ZGUW
50 kN Order no. 1-U2A/5 t/ZGUW
100 kN Order no. 1-Z4/100 kN/ZGUW
2 Application information
Force transducers of the U3 type series are suitable for measuring tensile and
compressive forces. They measure static and dynamic forces extremely
accurately and therefore require careful handling. You must take particular
care when transporting and installing the devices. If you knock or drop the
transducers, this could permanently damage them.
The housing provides an elaborate seal to protect the sensitive strain gauge
applications and it is essential that this is preserved. You must be particularly
careful with the base of the housing, as this is extremely thin.
The limits for the permissible mechanical thermal and electrical stresses are
stated in the Specifications. It is essential that these are taken into considera
tion in planning the measuring set‐up, during installation and finally, during
operation.

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3 Structure and mode of operation
3.1 Measuring element
The measuring element is a measuring spring made from stainless steel, to
which strain gauges (S/G) are applied. The S/Gs are arranged so that four of
them can be strained and the other four compressed when the transducer
reacts to a force.
3.2 Housing
The housing with the integrated measuring spring is completed underneath by
an attached base. This base is extremely thin and must not be loaded
centrally (see Page 11). It should be protected against mechanical damage.
Pressure compensation hole
Fig. 3.1 Position of housing base

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4 Conditions on site
4.1 Ambient temperature
The effects of temperature on the zero signal and on the sensitivity are com
pensated. To achieve optimal measurement results the nominal temperature
range must be maintained. Temperature‐induced measurement errors are
caused by heating (e.g. radiant heat) or cooling on one side. A radiation bar
rier and all‐round thermal insulation will produce a marked improvement, but
should not form a force shunt.
4.2 Moisture
Extreme humidity or a tropical climate should be avoided if this means that the
classified limit values are exceeded (degree of protection IP65 under DIN
EN 60529).
NOTE:
Moisture must not be allowed to penetrate the free end of the connection
cable or get into the pressure compensation hole.
4.3 Deposits
Dust, dirt and other foreign bodies must not be allowed to accumulate such
that they divert part of the measured force onto the housing and so falsify the
measured value (force shunt).
NOTE:
Foreign bodies must not be allowed to clog the gap beneath the flange
surface.
Pressure compensation hole

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5 Mechanical installation
5.1 Important measures for installation
•Handle the transducer with care.
•Do not overload the transducer.
•Welding currents must not be allowed to flow over the transducer. If there is
a risk that this might happen, you must use a suitable low‐ohm connection
to electrically bypass the transducer. HBM, forexample, provides the highly
flexible EEK ground cable, which can be screwed on, both above and
below the transducer.
WARNING
If there is a risk of breakage through overload on the transducer and
thus a risk to persons, additional safety measures are to be taken.
5.2 General installation guidelines
The direction of measurement in which the forces work should be as much
towards the transducer as possible. Torsion and bending moments, eccentric
loading and transverse forces may result in measurement errors and if the
limit values are exceeded, could destroy the transducer.
The transducer can take up 100 % (80 % at 50 kN, 50 % at 100 kN) of its
nominal force as transverse force by reference to a force introduction point on
the force‐introduction surface (see diagram Fig. 5.1), without losing its
mechanical competence.
Transverse force
Fig. 5.1 Transverse force introduction

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NOTE:
In the case of transducers of nominal forces 20 kN, 50 kN and 100 kN,
the base area is not flat.
55H8
∅70"0.1 Force must only be
introduced here
0.5
Centre the U3 over diameter 55H8.
Do not load centrally here.
Nominal force 20 kN, 50 kN and 100 kN:
Fig. 5.2 Base of the U3

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5.3 Installation for tensile loading/compressive loading
5.3.1 Installation without adapter
The transducer is screwed directly (by flange or base) on to an existing
structural element (e.g. profile, cover, plate). This type of installation enables
the transducers to measure axial forces in the tensile force and compressive
force directions. Alternating loads can also be recorded perfectly. The
transducer must be installed without axial play for this. For dynamic sustained
loading, the top and bottom threaded connectors must be prestressed by lock
nuts to above the maximum load.
drawing offset by
45oor 22.5oMA
MA
provided by customer
provided by customer
Flange
base
Fig. 5.3 Installation for compressive loading
Nominal force (kN) Starting torque MA(NVm) Thread1)
0.5 - 10 54 x M5
20 40 4 x M10
50 40 8 x M10
100 94 8 x M102)
1) Take note of the thread depth (see Dimensions, Page 18)
2) 12.9 DIN912 galvanized
HBM supplies knuckle eyes as mounting accessories for transducers of the
U3 type series. Knuckle eyes are suitable for use during quasi‐static loading
(10 Hz alternating loads). In the case of dynamic loading at a higher
frequency, you should use flexible tension bars. Knuckle eyes prevent the
introduction of torsional moments and when 2 knuckle eyes are used, stop
bending moments and transverse and angular loading being introduced in the
transducers.

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5.3.2 Installation with adapter and knuckle eye
If the transducer is to be tensile force loaded, it can be mounted with an
adapter (HBM accessory) and a knuckle eye. There is a centre hole (34H8 mm
or 55H8 mm, effective depth approx. 1 mm) on both sides of the transducer.
H
drawing offset by
45oor 22.5o
M2 (MA)
provided by customer
lock nut, MB
ZGUW/1 - 5T/100 kN
M1
(MA)
adapter
flat
base
flange
Fig. 5.4 Installation for tensile loading
Nominal force
(kN) HMax
(mm) Starting torque
MA(NVm) Starting torque MB(NVm) Screws for adapter mounting
M1 M2
0.5 - 10 108 5 60 M5x12 M5
20 170 40 300 M10x25 M10
50 180 40 500 M10x25 M10
100 187 94 1000 M10x25 M10
Attaching the knuckle eye:
•Screw the correct adapter (dependent on nominal force!) to the U3 (please
note screw length, screw quality A2-70, at 100 kN. 12.9 DIN912,
galvanized)
•Turn the lock nut back as far as the eye
•Screw the knuckle eye into the adapter as far as the stop
CAUTION
Do not apply force to the transducer flange.
•Unscrew knuckle eye 1 to 2 turns and align
•Load eye with nominal load
•Tighten lock nut (MB, lock using the flat of the adapter)
CAUTION
When locking with the lock nut, under no circumstances let the torque
be transmitted through the transducer.

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5.3.3 Installation with two knuckle eyes
H
M2 (MA)
MB
MB
M1 (MA)
base
flange
Fig. 5.5 Installation for tensile loading with two knuckle eyes
Nominal
force (kN) H(mm) Starting torque MA
(NVm) Starting torque MB (NVm) Screws for adapter
mounting
M1 M2
0.5 - 10 153 5 60 M5x12 M5x16
20 232 40 300 M10x25 M10x30
50 256 40 500 M10x25 M10x30
100 300 94 1000 M10x25 M10x30
Attaching the knuckle eye:
•Screw the correct adapter (dependent on nominal force!) to the U3 (please
note screw length)
•Turn the lock nut back as far as the eye
•Screw the knuckle eye into the adapter as far as the stop
CAUTION
Do not apply force to the transducer flange.
•Unscrew knuckle eye 1 to 2 turns and align
•Load eye with nominal load
•Tighten lock nut (MB, lock using the flat of the adapter)
CAUTION
When locking with the lock nut, under no circumstances let the torque
be transmitted through the transducer.

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6 Electrical connection
The transducers come complete with a 3 m long cable with free ends. The
cable shielding is connected in accordance with the Greenline concept. This
means that the measurement system is surrounded by a Faraday cage and is
not affected by electromagnetic interference.
Connectors to CE standard are to be fitted at the free cable end of the trans
ducer. The shielding is here to be laid over the whole area. If a different con
nection technique is used then good EMC shielding is to be provided in the
wiring loom, the shielding again being laid over the full area (see also HBM
Greenline Information, document G36.35.0).
6.1 Instructions for cabling
•Always use shielded, low‐capacity measurement cable, available from
HBM.
•Do not lay measurement cable parallel to high‐voltage power lines or
control circuits. If this is not possible (e.g. in cable ducts) protect the
measurement cable, e.g. with armoured steel tube and maintain a minimum
distance of 50 cm from the other cables. High voltage power lines and
control lines should be twisted (15 turns per metre).
•Avoid stray fields of transformers, motors and contactors.
•Do not earth transducer, amplifier and display device more than once. All
the devices in the measuring chain are to be connected to the same
earthed conductor.
•The screen of the connection cable is connected to the transducer housing.

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Connecting to terminals:
1. You can get to the screen through a slit in the cable sheath (see Fig. 6.1).
2. Lay the screen flat on the housing frame.
Attaching to a connector:
Lay the cable shield flat on the connector housing.
Cable sheath cut open at the circumference
and pushed forward by approx 2mm
100
10
10
2
Fig. 6.1: Slit cable sheath
wh (white)
bk (black)
rd (red)
bl (blue)
gn (green)
gy (grey)
ye (yellow)
Measurement signal (+) UA
Excitation voltage (+) UB
Sensor circuit (-)
Sensor circuit (+)
Excitation voltage (-) UB
Measurement signal (-) UA
Cable shielding, connected to housing
Six‐wire connection
Fig. 6.2: Pin assignment for the U3

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7 Specifications (VDI/VDE2638)
Type U3
Nominal force Fnom kN 0.5 1 2 5 10 20 50 100
Accuracy class 0.2
Nominal sensitivity Cnom mV/V 2
Relative sensitivity deviation
compressive force dc%t"0.2
Relative tensile/compressive
force sensitivity difference dzd %t2t1
Relative zero signal deviation ds.o %t1
Hysteresis (0.2Fnom to Fnom) u % t0.2
Linearity deviation compressive
force dlin %t0.2
Linearity deviation tensile force dlin %t0.3 t0.2
Effect of temperature on
sensitivity/10 K by reference to
sensit. TKc
%t0.2 t0.1
Effect of temperature on zero
signal/10K by reference to sensitivity
TK0%
t0.1
Effect of eccentricity at 1 mm dE%t"0.1
Effect of transverse forces
Transverse force 10 % Fnom1) dQ%t"0.1 t"0.2
Creep over 30 min dcrf+E %t"0.1
Input resistance ReΩu345
Output resistance RaΩ300-400
Isolation resistance Ris Ωu2 x 10 9
Reference excitation voltage Uref V 5
Operating range of the excit. volt. BU.GT V0.5 bis 12
Nominal temperature range Bt.nom oC[oF] -10 ... +70 [+14 ...+158]
Operating temperature range Bt.G oC[oF] -30 ... +85 [-22 ...+185]
Storage temperature range Bt.S oC[oF] -50 ... +85 [-58 ...+185]
Reference temperature tref oC[oF] +23 [+73]
Maximum operating force (FG) % 130 150 130
Limit force (FL) % 130 150 130
Breaking force (FB) % u300 250
Static lateral limit force1) (FQ) % 100 80 50
Permissible eccentricity eGmm 25 40 32 20
Nominal displacement Snom mm t0.08 t0.1
Fundamental resonance
frequency fGkHz 1.3 2.1 3.1 5.2 7.1 3.7 5.7 7.25
Rel. permissible vibrational
stress Frb % 100 160
Weight kg app. 0.6 app. 2.5
Degree of protection to DIN EN60529 IP65
Cable length, six‐wire connection m 3
1) by reference to a force introduction point on the force‐introduction surface

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8 Dimensions
U3:50 kN/100 kN
U3: 0.5 - 20 kN
4 x 90o
8 x 45o** only at 20, 50 kN and 100 kN
45o
22.5o
Cable length 3 m
Cable length 3 m
∅K
∅K
∅A
∅C
M
∅C
∅K
∅B
Mini screwed joint M8x1; a.f.11
∅H
G
D
F
E
0.5*
approx. 3.5
1.5
M
3
Nominal force ∅A∅B∅CH8 D E F G ∅H∅K"0.1 M
U3/0.5-10 kN 54 50 34 8.5 5 13 47 5.5 42 M5
U3/20 kN
95 90 55 14 5.5 20.5 72 11 70 M10
U3/50 kN
U3/100 kN

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Mounting accessories
Knuckle eye ZGUW
Material: tempering steel, galvanised; rolled steel
and PTFE/bronze fabric foil
Q
S
P
R
Adapter
A
C
Df8
M
K
L
a./f.
N
W
B
∅
H7
HD
M
F
G
A
a.f.
Knuckle eye
Nominal
force (kN) A∅BH7 D F G H M X W a./f. Weight (kg)
0,5...10 33.5 12 32 54.5 70.5 12 M12 7 16 19 0.1
20 47 20 50 79.8 104.8 18 M20x1.5 9 25 30 0.4
50 57 25 60 94.5 124.5 22 M24x2 10 31 36 0.6
100 66 30H7 70 110 145 25 M30x2 24 37 46 1.1
Adapter
Nominal
force
(kN)
∅A∅C∅Df8 M∅K∅L∅N P Q R S a./f. Weight1)
(kg)
0.5...10 50 42 34 M12 14 22 4x5.5 4.5 19 25.1 0.9 19 0.15
20 90 70 55 M20x1.5 22 34 4x11 4.5 15 40.1 0.9 30 1.3
50 90 70 55 M24x2 26 42 8x11 6 20 45.1 0.9 36 1.45
100 90 70 55 M30x2 32 47 8x11 6 20 45.1 0.9 41 1.45
1) including screws

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