Ambient pressure effect on zero signal (%/kPa)

Variation of the zero signal of the force trans-
ducer, in relation to the characteristic value, due to
variation of the ambient pressure, pi by 1 kPa,
within a defined ambient pressure range after
steady states have been adjusted.

pK₀= S_0,(pi+10kPa) - S _0,pi                                                                                                                     C_nom

 (The greatest value of pK0 and the ambient pres-
sure range are to be stated.)

Bending moment effect(AE/N·m)

Deviation of the output signal of the force trans-
ducer due to a bending moment.

Bending moment limit (N·m)

Permissible static bending moment which when
the transducer is simultaneously loaded to rated
force does not produce any permanent significant
changes in the metrological properties of the force
transducer up to rated force.

Breaking force(N)

Force of the force transducer above which me-
chanical destruction is to be reckoned with.

C

Characteristic curve

Curve describing the dependence of the output
signal on force.

Characteristic value (AE)

Output signal at rated force, F_nom, decreased by
the zero signal in the mounted state S_F0.

Characteristic value range (AE)

Range within which the characteristic value of the
transducer lies. (This statement is common prac-
tice for transducers whose characteristic value has
not been adjusted.)

Compression force(N)

Force in the direction of compression acting onto
a compression force or universal force transducer

Creep under load

d_cr,F= S₃ - S₂                                                                                                                                S₂ -S₀

The rise time, tA, and the weighting time, tB, are to
be stated.
B
Note: Loading should preferably take place with rated force.
For this, high constancy is demanded for force generation as
can usually be ensured only using direct loading devices. See
also Section 3.9.7: Creep when load is relieved.

Creep when load is relieved

d_cr,E = S₆ - S₇                                                                                                                                S₂ - S₀

The fall time, t_A, and the weighting time, t_B, are to
be stated.
Note: Loading should preferably take place with rated force.
For this, high constancy is not demanded for the force genera-
tion. Fluctuations by ±2 % can be neglected so that it is also
possible to use good reference loading devices.                                                                   
Creep under load and when the load is relieved
are, in good approximation, equal in size. How-
ever, attention has to be paid to short-time drift
and adiabatic effects.

Electromagnetic
compatibility (EMC)

Details regarding immunity from interference and
electromagnetic emissions and incident radiation.

Eccentricity effect (AE/mm)

Output signal of the force transducer at rated force
due to a defined displacement of the force action
line parallel to the measurement axis. The greatest
eccentricity effect in the plane vertical to the mea-
surement axis is to be stated.

Excitation voltage effect on zero signal (%)

Variation of the zero signal of the force trans-
ducer, in relation to the rated characteristic value,
due to variation of the excitation voltage in the
rated range of the excitation voltage, B_{U, nom}.
The voltage range is to be stated.

Excitation voltage effect on characteristic value (%)

Relative variation of the characteristic value of the
force transducer due to variation of the excitation
voltage in the rated range of the excitation voltage,
B_{U, nom}.

d_C,U = C_{U max} - C _{U min}                                                                                                                                                C_nom

The voltage range is to be stated.

Frequency effect of excitation voltage on zero signal (%)

Maximum deviation of the zero signal, in relation
to the rated characteristic value, due to variation of
the carrier frequency of the excitation voltage.
3.8.3.4
The frequency range is to be stated.

Fall time

t_A= t₂- t₀  or   t₆ - t₄

Note: In practice, this period of time is determined by the
speed with which the loading device can effect the variation
and by the time necessary for reaching steady-state force. It
should ideally be zero but has to be in any case clearly
smaller than the provided weighting time, t_B.
t_A << t_B

Force (N)

Vectorial physical quantity with point of applica-
tion, direction of action and amount
(1 N = 1 kg·m·s^–2).

Force introduction effect

Maximum deviation of the output signal of the
force transducer when using different kinds of
force introduction, in relation to the output signal
decreased by the zero signal in the mounted state
providing correct force introduction.
Note: To investigate a compression force transducer, the
combinations of plane and conical force introduction bodies
on the upper and lower side of the force transducer as repre-
sented in Figure 3 are to be preferably used. For the conical
force introduction bodies both negative and positive cones
shall be used. The recommended included angle of the cone is
0,2°. To compare the values of the force introduction effect,
the investigation shall be carried out at 50 % of the rated for-
ce.

Force limit (N)

Force above which permanent significant changes
in the metrological properties of the force trans-
ducer are to be reckoned with.

Force measurement range (N)

Measurement range in which a force transducer is
used. A force transducer may have several meas-
urement ranges. Within these ranges the associ-
ated error limits have to be complied with. Each
measurement range is limited by an initial value
F_A and a final value F_E.
Note: To ensure comparability of the metrological properties
of different force transducers, the measurement range is to be
weighted from F_A = 0,2·F_nom to F_E = F_nom
.
 

Force variation time (s)

t_F= t₁- t₀  or  t₅ - t₄

Frequency effect of excitation voltage on
characteristic value (%)

Maximum deviation of the characteristic value, in
relation to the rated characteristic value, due to varia-
tion of the carrier frequency of the excitation voltage.
The frequency range is to be stated.

Fundamental resonant frequency ( Hz or s^–1)

Resonant frequency with which the unloaded
force transducer without force introduction parts
oscillates after abrupt excitation in the direction of
the measurement axis, its base, serving for fasten-
ing, being coupled to a mass of appropriate size.
Note: A force transducer has several natural frequencies.
These frequencies change in dependence on the clamping
parts coupled.

Initial force signal rest (%)

Difference of the zero signals, in relation to the
rated characteristic value, in the mounted state
before and after loading with rated force, after
creep effects, if any, have declined.

Input resistance (Ω)

Ohmic resistance of the force transducer meas-
ured between the excitation/supply voltage con-
nections.

Insulation resistance (Ω)

Ohmic resistance, measured between the connect-
ing lines and the elastic body of the force trans-
ducer. The test voltage is to be stated.

Lateral force effect (AE/N)

Relative deviation of the output signal of the force
transducer due to a lateral force of 10 % of the
acting force. The lateral force shall be applied ver-
tical to the measurement axis in the point of force
introduction. The greatest lateral force effect in the
plane vertical to the measurement axis is to be
stated.

Lateral force limit (N)

Permissible static lateral force which, when the
transducer is simultaneously loaded to rated force,
does not produce any permanent significant chan-
ges in the metrological properties of the force
transducer up to rated force.

Lower limit of measurement range (N)

Initial value of the force measurement range.

Mass (kg)

Mass of the force transducer without force intro-
duction parts.

Maximum operating force (N)

Greatest force of the force transducer up to which
there is a defined and repeatable relation between
force and output signal but any protection against
overloading does not yet operate.

Measuring spring rigidity (N/mm)

Ratio of the force to the axial deformation of the
measuring spring, measured between the positions
of force introduction and release (in the case of
defined adaptations).

Mechanical shock resistance

Resistance of the force transducer to impact load
(mechanical shocks) without permanent signifi-
cant changes in the metrological properties of the
force transducer being produced up to rated force.
Note: The severity level used in testing according to DIN
EN 60068-2-27 is to be stated (number of shocks, duration of
mechanical shocks, shock acceleration).

Mounting effect on zero signal (%)

Relative variation of the zero signal, in relation to
the rated characteristic value, when fastening the
force transducer to a base plate according to the
mounting instructions, e. g. using screws or
clamping pads.

Operating range of excitation voltage (V)

Range of the excitation voltage in which the force
transducer may be operated tolerating higher error
limits without permanent significant changes in
the transducer's metrological properties being de-
tectable when using the transducer again in the
rated excitation voltage range.
Note: For force transducers with integrated electronics, the
supply voltage (Section 3.6.14) is substituted for the excita-
tion voltage.

Operating temperature range (°C)

Range of the ambient temperature in which the
force transducer may be operated tolerating higher
error limits without permanent significant changes
in the metrological properties of the transducer
being detectable when using the transducer again
within the rated temperature range.

Output resistance (Ω)

Ohmic resistance of the force transducer, meas-
ured between the output voltage connections.

P

Proportionate moving mass (kg)

That part of the mass of the force transducer by
the movement of which additional forces of iner-
tia are generated (without additional masses such
as force introduction parts and coupling mem-
bers). mmess is dependent on the coupling side se-
lected. The latter is to be stated.

Permissible eccentricity of force introduction (mm)

Permissible displacement of the force action line
parallel to the measurement axis of the force
transducer at rated force without permanent sig-
nificant changes in the metrological properties of
the force transducer being produced up to rated
force.

Permissible oscillation stress (%)

Fluctuation, in relation to rated force, of a sinu-
soidally varying pulsating or alternating force
suffered by the force transducer when stressed
over at least 107 stress cycles without permanent
significant changes in the metrological properties
of the force transducer being produced up to rated
force.

Position effect on zero signal. (AE)

Deviation of the zero signal, in relation to the
rated characteristic value, due to a change in the
position of the force transducer in the gravitational
field of the Earth.
The change in position is to be stated, e. g. over-
head mounting.

Protection

Degree of protection provided by the enclosure
according to DIN EN 60529. It indicates to what
extent the force transducer is protected from hu-
midity and dust as well as from the ingress of solid
foreign bodies.

Pulsating force (N)

Force varying with time, without zero crossing
(fluctuation); in analogy to the pulsating stress
according to DIN 50100.

Relative creep

By creep the time-dependent variation of the out-
put signal of the force transducer after force varia-
tion is understood. A distinction is to be made be-
tween:
• creep under load
• creep when load is relieved
Note: To obviate the prior history of the force transducer, the
latter is to be loaded once with rated force. After preloading,
five times the time of preloading must elapse before starting
the measurement proper.

Rated characteristic value (AE)

Target value (theoretical value) for the character-
istic value.

Rated displacement (mm)

Spring excursion of the outer force introduction
points or surfaces of the force transducer in the
direction of measurement relative to one another
due to loading with rated force. (The mounting
and measurement conditions are to be stated).

Rated force (N)

Greatest force for which the transducer is nomi-
nally designed, i. e. up to which the manufac-
turer’s metrological specifications are complied
with.

Rated range of excitation voltage (V)

Range of the excitation voltage in which the force
transducer complies with the error limits for its
technical data.
Note: For force transducers with integrated electronics, the
supply voltage (Section 3.6.14) is substituted for the excita-
tion voltage.

Rated temperature range (°C)

Range of the ambient temperature in which the
force transducer complies with the error limits for
the temperature-dependent technical data.

Reference air humidity (%)

Relative humidity of the surrounding air for which
the technical data of the force transducer are valid.

Reference characteristic value (AE)

The value indicated at rated force, calculated with
the aid of the reference straight line (Section 3.2.6).
The method to determine the reference straight line
and the measurement values used for this purpose
are to be stated (only load or load/load relief).

Reference excitation voltage (V)

Excitation voltage (r.m.s. value, frequency, and
waveform) for which the technical data of the
force transducer are valid.

Reference straight line

Straight line describing (as an approximation of
the characteristic curve) the dependence of the
output signal on force. It is determined from a
number of measurement values (each decreased
by the zero signal in the mounted state SF0 and/or
averaged from several series of measurements
carried out using the same loading sequence) and
always passes through the coordinate origin (see
Figure 2). The reference straight line can take
account only of the values measured under load or
under load/load relief conditions, i.e. including
hysteresis. The procedure applied is to be stated.
Note: For computational determination different procedures
are available. The procedure selected is to be stated.
Examples:
a) Preferably: A first-order fitting function whose slope is
fixed in such a way that the sum of the squares of all signal
deviations from the reference straight line yields a minimum
(in the literature: least-squares method).
b) A first-order fitting function whose slope is fixed in such a
way that the amounts of the maximum positive and negative
signal deviations from the reference straight line are equal
(the maximum amount of the deviation becomes minimum;
in the literature: optimum straight line).
c) A straight line through the origin and the characteristic
value (in the literature: starting/end point method).

Reference temperature (°C)

Temperature for which the technical data of the
force transducer are valid.

Relative characteristic value difference, tension/
compression force (%)

Difference between the characteristic values under
tension and compression force, in relation to the
characteristic value for compression force.

Relative deviation of zero signal (%)

Maximum deviation of the zero signal in the re-
moved state, in relation to the rated characteristic
value, from the value zero.

Relative deviation of characteristic curve (%)

Deviation of a characteristic curve value, recorded
over one loading cycle, from the reference straight
line (see Section 3.2.6), in relation to the appro-
priate value of the reference straight line.
(The maximum relative deviation of the character-
istic curve, d_{k max}, for the force measurement range
from 0,2 · F_nom to 1,0 · F_nom as well as the method
for determining the reference straight line are to
be stated.)

Relative error of characteristic value (%)

Relative deviation of the characteristic value from
the rated characteristic value. (This statement is
common practice for transducers whose character-
istic value has been adjusted.)

Relative linearity error (%)

Maximum deviation of a characteristic curve of a
force transducer, determined at increasing force,
from the reference straight line (Section 3.3.6), in
relation to the upper limit of the measurement
range used. The measurement range is to be sta-
ted.

Relative repeatability error in unchanged mounting
position (%)

Maximum difference of the output signals at equal
force, determined from several series of measure-
ments without the mounting position being changed,
in relation to the mean output signal decreased by
the zero signal in the mounted state (Section 3.3.2).
The number of the measurement series is to be stated.
brg is a measure of the repeatability.

Relative reproducibility error in different mounting
positions (%)

Maximum difference of the output signals at equal
force in different mounting positions, in relation
to the mean output signal decreased by the zero
signal in the mounted state (Section 3.3.2). The
number of the series of measurements and of the
positions in which the measurements are carried
out are to be stated.
brv is a measure of the reproducibility.

Relative reversibility error (%)

Difference of the output signals of an increasing
and decreasing series at equal force, F, in relation
to the output signal at increasing force, decreased
by the zero signal in the mounted state. (For the
determination of the reversibility error, the load-
ing cycle up to rated force is to be plotted. The
greatest relative reversibility error, v_max, and the
force measurement range used are to be stated.

Relative reversibility error at 0,5 Fnom (%)

Reversibility error according to Section 3.3.10 at
0,5 · F_nom.

Relative zero signal hysteresis (%)

Zero signal difference in the mounted state, over a
complete alternating force cycle with Fnom, in rela-
tion to the rated characteristic value.

Rise time

t_A = t₂ - t₀  or  t₆ - t₄

Note: In practice, this period of time is determined by the
speed with which the loading device can effect the variation
and by the time necessary for reaching steady-state force. It
should ideally be zero but has to be in any case clearly
smaller than the provided weighting time, t_B.

t_A << t_B

Storage temperature range (°C)

Range of the ambient temperature in which the
mechanically and electrically unstressed force
transducer may be stored without permanent sig-
nificant changes in the metrological properties of
the transducer being detectable when using the
transducer again within the rated temperature
range.

Storage effect on characteristic value (%)

Relative deviation of the characteristic value of the
force transducer per year when stored under refer-
ence conditions without being loaded during this
time.

Storage effect on zero signal (%)

Maximum deviation of the zero signal of the force
transducer, in relation to the rated characteristic
value, over one year when stored under reference
conditions without being loaded during this time.

Supply voltage (V)

Operating voltage (mains or battery supply) of the
measuring amplifier of the measuring chain.

Temperature effect on characteristic value (%/10 K)

Relative variation of the characteristic value of the
force transducer due to variation of the ambient
air, T_i by 10 K, within a defined temperature range
after steady states free of gradients have been ad-
justed.

TK_c = C_(Ti+10K) - C_Ti                                                                                                                                                                    C_Ti

(The maximum value of TKC and the temperature
range are to be stated.)

Temperature effect on zero signal (%/10K)

Variation of the zero signal of the force trans-
ducer, in relation to the rated characteristic value,
due to variation of the ambient temperature, Ti by
10 K, within a defined temperature range after
steady states free of gradients have been adjusted.

TK₀ = S_0,(Ti+10K) - S_0,Ti                                                                                                                                   C_nom

(The greatest value of TK0 and the temperature
range are to be stated.)

Tension force (N)

Force in the direction of tension acting onto a ten-
sion force or universal force transducer.

Torque effect (AE/N·m)

Relative deviation of the output signal of the force
transducer due to a torque around the measure-
ment axis.
The torque is to be stated.

Torque limit (N·m)

Permissible torque around the measurement axis
of the force transducer which when the transducer
is simultaneously loaded to rated force does not
produce any permanent significant changes in the
metrological properties of the force transducer up
to rated force.

U

Unit of indication (AE)

Unit in which the output signal of the force trans-
ducer is indicated (e. g. N; mV/V; V; mA; pC).

Upper limit of measurement range (N)

Final value of the force measurement range.

Vibration resistance

Resistance of the force transducer to forced sinu-
soidal oscillations of specified severity without
permanent significant changes in its metrological
properties being detectable up to rated force.
Note: The severity level used in testing according to DIN
EN 60068-2-6 is to be stated (frequency range, amplitude of
the acceleration, duration of stress).

W

Weighting time (s)

t_B = t₃ - t_s  or  t₇ - t₆

Zero signal when removed (AE)

Output signal of the unloaded force transducer,
without mounting parts.

Zero signal when mounted (AE)

Output signal of the force transducer when not
mechanically loaded, with mounting parts, at the
beginning of a loading cycle.