HBM Z8 User manual

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Force transducer
Z8
Mounting instructions
A3764-1.0_en/de

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English
1 Safety instructions 3........................................
2 Scope of supply 6..........................................
3 Application information 7...................................
4 Structure and mode of operation 8...........................
4.1 Measuring element 8.........................................
4.2 Housing 8..................................................
5 Conditions on site 9........................................
5.1 Ambient temperature 9.......................................
5.2 Moisture 9..................................................
5.3 Deposits 10..................................................
6 Mechanical installation 10....................................
6.1 Important measures for installation 10...........................
6.2 General installation guidelines 11...............................
6.3 Installation for tensile loading/compressive loading 12.............
6.3.1 Installation 12................................................
6.3.2 Measuring direction, preferred direction, load direction 12..........
7 Electrical connection 14......................................
7.1 Instructions for cabling 14......................................
7.2 Connecting several transducers in parallel 16.....................
8 Specifications (VDI/VDE2638) 17..............................
9 Dimensions 18..............................................
10 Declaration of conformity 19.................................

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1 Safety instructions
Use in accordance with the regulations
Force transducers are designed for force measurements
on test benches/mounting or test devices and general
laboratory applications. Use for any additional purpose
shall be deemed to be not in accordance with the regula
tions.
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 mean
ing of its use as intended. Proper and safe operation of
this transducer requires proper transportation, correct
storage, assembly and mounting and careful operation
and maintenance.
General dangers of failing to follow the safety
instructions
The Z8 force transducer corresponds to the state of the
art and is fail‐safe.
The transducers can give rise to remaining dangers if
they are inappropriately installed and operated by un
trained personnel.
Everyone involved with the installation, commissioning,
maintenance or repair of a force transducer must have
read and understood the Mounting Instructions and in
particular the technical safety instructions.

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Remaining dangers
The scope of supply and performance of the transducer
covers only a small area of force measurement tech
nique. In addition, equipment planners, installers and op
erators should plan, implement and respond to the safety
engineering considerations of force measurement tech
nique in such a way as to minimize remaining dangers.
Prevailing regulations must be complied with at all times.
There must be reference to the remaining dangers con
nected with force measurement technique.
In these mounting instructions remaining dangers are
pointed out using the following symbols:
WARNING
Meaning: Dangerous situation
Warns of a potentially dangerous situation in which fail
ure to comply with safety requirements can result in
death or serious physical injury.
CAUTION
Meaning: Possibly dangerous situation
Warns of a potentially dangerous situation in which fail
ure to comply with safety requirements could lead to
damage to property, slight or moderate physical injury.

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Note
Means that important information about the product or its
handling is being given.
Meaning: CE mark
The CE mark signals a guarantee by the manufacturer
that his product meets the requirements of the relevant
EC directives (see Declaration of conformity at the end of
this Operating Manual).
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 dismounting the adapter in accordance with
Chapter 6 excluded.
Qualified personnel
This instrument is only to be installed by qualified person
nel 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 reg
ulations 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.

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Conditions on site
Protect the transducer from damp and weather influ
ences such as rain, snow, etc.
Maintenance
The Z8 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 associ
ations must be taken into consideration.
2 Scope of supply
S1 Z8 force transducer with a permanently mounted
connection cable
S1 operating manual Z8
STest protocol

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3 Application information
The transducers are fixed and loaded as cantilever
beams. The specified sensitivity tolerance applies for
loading in the preferred measuring direction (arrow V in
Fig. 6.1). But you can also measure in the opposite direc
tion, e.g. for alternating load. In accordance with their
intended application, the transducers are calibrated as
force‐proving instruments in units of force.
The force transducers measure dynamic loading just as
exactly as static loads. The high spring rates (small
amounts of travel) of the transducers are a particular ad
vantage here.
As they are precision measuring devices, force trans
ducers need to be handled carefully during transportation
and mounting, as knocking or dropping the transducers,
for example, can permanently damage them. Sudden
load changes (e.g. load applied in ”free fall”) in measur
ing mode can also cause an unexpected overload with
lasting damage. Where it is not possible to exclude this
type of sudden load change with certainty, they have to
be intercepted.
HBM force transducers are maintenance free and can
even be mounted in places where access is difficult.
Their electrical measurement signals can be transmitted
to remote measuring points and stations where they can
be displayed, recorded and used for control tasks.
Because of the open transducer mounting, you should
keep to the permitted field of application. The transducer
should not be operated under rough conditions or in a
corrosive atmosphere. The conditions of use can be
found in the specified climatic utilization category
(see section 5.2).

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The limits for the permissible mechanical thermal and
electrical stresses are stated in the Specifications. It is
absolutely essential to comply with them. Please take
this into account when planning the measuring set‐up,
during installation and finally, during operation.
4 Structure and mode of operation
4.1 Measuring element
The measuring element is a measuring spring made from
a high‐strength aluminum alloy, to which two half bridge
strain gages (S.G.s) have been applied. For the Z8 trans
ducers, the shape of the measuring spring that is used is
a double bending beam. The S.G.s are arranged so that
two of them are extended and the other two are com
pressed when the measuring spring is loaded in the
measuring direction. A cover protects the S.G.s from
moisture. The user must take suitable measures to en
close the transducer to protect it against corrosive media.
Force shunts must be avoided here.
4.2 Housing
The anodized aluminum housing is pushed over the
measuring element, open towards the load introduction
side and closed by the measuring element at the other
end. It protects the S.G. application against mechanical
stresses.

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5 Conditions on site
5.1 Ambient temperature
The influence of temperature on the measurement signal
is compensated.
To achieve optimal measurement results the nominal
temperature range must be maintained. Temperature‐in
duced measurement errors are caused by heating (e.g.
radiant heat) or cooling on one side. A radiation shield
and all‐round thermal insulation will produce a marked
improvement, but should not form a force shunt.
The ambient pressure (in air) has no effect on the meas
urement accuracy
5.2 Moisture
Climatic utilization category HSF in accordance with DIN
40040 states that the transducer can be operated in an
operating temperature range of ‐25 °C to +70 °C. The
humidity loading in the average annual temperature must
not exceed 75%. On 30 days, distributed over the year,
the maximum value of the sustained relative humidity of
air can be 95%, on the remaining days, a mere 85%.
Transducer condensation is not permitted.
Note
Moisture must not be allowed to penetrate the free end of
the connection cable or the pressure compensation hole.

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5.3 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).
6 Mechanical installation
6.1 Important measures for installation
STreat the transducer gently. When handling and
mounting, no forces and moments worth mentioning
should be directed over the sensitive precision meas
uring element below the aluminum housing.
STransducers with nominal loads 50N and 100N are by
nature very vulnerable to overloads and should there
fore always be handled particularly carefully.
SThe base must be inflexible against the intended
loads.
SThe transducer seating must be totally flat and - just
like the transducer mounting surface - be absolutely
clean.
SThe transducer seating must be totally flat and - just
like the transducer mounting surface - be absolutely
clean.
SDo not overload the transducers, not even temporar
ily, for example by unevenly distributed bearing loads.
SAbove all, when there are more than three trans
ducers (statically indeterminate storage) get the load
introduction points on one level. With a central load

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ing, the output signals of all the transducers should be
approximately the same.
SDuring, or immediately after installation, each trans
ducer should be bypassed by sufficient stranded cop
per wire, so that no welding current or lightning stroke
current can possibly flow through the transducer and
weld the load introduction point.
CAUTION
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.
6.2 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 trans
ducer.
Thermal expansions and other displacements can, espe
cially in the case of several bearing points, cause consid
erable transverse loading if both ends of the transducer
are rigidly held.

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6.3 Installation for tensile
loading/compressive loading
6.3.1 Installation
Z8 transducers are held at the end over the two mounting
holes by steel screws. The threads should be locked by a
liquid material such as Loctite 242 or similar. For the
face‐down arrangement, preferred direction V is decisive
(see Fig. 6.1).
When the transducer - especially with regard to a correct
load direction – is finally aligned and securely clamped, is
it advisable to fix or mark its position with immovable limit
stops at the side and at the end.
6.3.2 Measuring direction, preferred direction, load
direction
The measuring direction is the axis of the through hole at
the ”free end” of the transducer. The preferred measuring
direction V (in Fig. 6.1) corresponds to this axis.

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V = preferred measuring direction; L = load
Fig. 6.1 Measuring direction
If load direction L along the transducer axis is moved par
allel to the preferred measuring direction (in Fig. 6.1 on
the right), then the combined error can change by a max
imum of 0.005% per 10 mm and the sensitivity can
change slightly: by a maximum of ±0.03% per 10 mm
distance between the preferred measuring direction and
the actual measuring direction. This distance must be no
more than 25 mm.
Load directions offset vertically to the transducer axis
(figure 1 on the left) cause torsional moments. A lateral
movement of 10mm can worsen the combined error up to
±0.005% from the nominal sensitivity and modify the
sensitivity by ±0.05%. The maximum lateral offset at
which the nominal load should engage is 15 mm. Greater
torsional moments can damage the transducer perman
ently.

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7 Electrical connection
The transducers come supplied with permanently moun
ted connection cables with four free ends.
The cable shielding is connected in accordance with the
Greenline concept. This surrounds the measurement
system with a Faraday cage, electromagnetic
interference does not affect the measurement system.
You must install male connectors on the transducers with
free cable ends to be CE‐compliant. The shielding is here
to be laid over the whole area. If a different connection
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).
7.1 Instructions for cabling
SAlways use shielded, low‐capacity measurement
cable, available from HBM.
SDo 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 min
imum distance of 50 cm from the other cables. High
voltage power lines and control lines should be twis
ted (15 turns per meter).
SAvoid stray fields of transformers, motors and con
tactors.
SDo not earth transducer, amplifier and display device
more than once. All the devices in the measurement
chain are to be connected to the same grounded con
ductor.

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SThe screen of the connection cable is connected to
the transducer housing.
Connecting to terminals
1. You can get to the screen through a slit in the cable
sheath (see Fig. 7.1).
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 2 mm
100
10
10
2
Fig. 7.1 Slit cable sheath
WH (white)
BK (black)
RD (red)
BU (blue)
YE (yellow)
Measurement signal (+) UA
Excitation voltage (+) UB
Excitation voltage (-) UB
Measurement signal (-) UA
Cable shielding, connected to housing
Fig. 7.2 Z8 pin assignment

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When connecting to amplifiers with sensor circuits
(6‐wire connection technique), the sensor circuits should
be connected to the relevant bridge excitation circuits.
7.2 Connecting several transducers in
parallel
If you connect several transducers of the same nominal
load in parallel, in the case of even load distribution, they
can be loaded with an overall load that corresponds to
the total of the individual nominal loads. When loading
with the overall load, the parallel connection of the S.G.
transducers then has the output signal 2mV/V.
CAUTION
An overload of an individual transducer cannot be detec
ted at the output signal. You must therefore take relevant
safety precautions (mechanical overload stops).
The transducers are connected in parallel electrically, by
joining together the wire ends of the transducer connec
tion cable that have the same color. For interconnection,
HBM has the VKK terminal box in the program. The
cables between the transducers and the terminal box
must be of the same length.

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8 Specifications (VDI/VDE2638)
Type Z8
Nominal force Fnom N 50 100 200 500 1000
Output span Cnom mV/V 2 "0,5%
Effect of temperature on zero sig
nal/10K by reference to sensitivity
TK0%
"0,05
Effect of temperature on /sensitiv
ity 10K by reference to sensitivity
TKc%
"0,1
Linearity deviation dlin %"0,05
Zero output range BS.0 mV/V "0,1
Input resistance ReΩ400
Output resistance RaΩ348
Isolation resistance Ris Ω5 x 10 9
Reference excitation voltage Uref V 5
Operating range of the excitation
voltage
BU.GT V
0.5 to 12
Maximum operating force (FG) % 130
Breaking force (FB) % u200
Static transverse limit force by ref
erence to nominal load
(FQ) % 50
Rel. permissible vibrational stress
according to DIN 50100
Frb % 60
Nominal ”mwss” displacement,
typically
Snom mm 0,13
Reference temperature tref oC +23
Nominal temperature range Bt.nom oC-10 to +40
Operating temperature range Bt.G oC-25 to +70
Storage temperature range Bt.S oC-50 to +70
Weight g 105
Climatic utilization category in accordance with
DIN 40040 HSF
Degree of protection in accordance with DIN 40050 IP30

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9 Dimensions
PVC cable, 3.6mm Ø
1.5m long, free ends
View A

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10 Declaration of conformity

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