IEC 62047-20:2014

IEC 62047-20 ®
Edition 1.0 2014-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Semiconductor devices – Micro-electromechanical devices –
Part 20: Gyroscopes
Dispositifs à semiconducteurs – Dispositifs microélectromécaniques –
Partie 20: Gyroscopes
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IEC 62047-20 ®
Edition 1.0 2014-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Semiconductor devices – Micro-electromechanical devices –

Part 20: Gyroscopes
Dispositifs à semiconducteurs – Dispositifs microélectromécaniques –

Partie 20: Gyroscopes
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XA
ICS 31.080.99 ISBN 978-2-8322-1667-5

– 2 – IEC 62047-20:2014  IEC 2014
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Essential ratings and characteristics . 6
4.1 Categorization of gyro . 6
4.2 Absolute maximum ratings . 7
4.3 Normal operating rating . 8
4.4 Characteristics . 8
5 Measuring methods . 10
5.1 Scale factor . 10
5.1.1 Purpose . 10
5.1.2 Measuring circuit (circuit diagram) . 10
5.1.3 Measuring principle . 12
5.1.4 Measurement procedures . 21
5.1.5 Specified conditions . 23
5.2 Cross axis sensitivity . 24
5.2.1 Purpose . 24
5.2.2 Measuring circuit (circuit diagram) . 24
5.2.3 Principle of measurement . 25
5.2.4 Precautions to be observed during the measurements of the angular
rate applied . 27
5.2.5 Measurement procedures . 27
5.2.6 Specified conditions . 27
5.3 Bias . 28
5.3.1 Purpose . 28
5.3.2 Measuring circuit . 28
5.3.3 Principle of measurement . 30
5.3.4 Measurement procedures . 35
5.3.5 Specified conditions . 37
5.4 Output noise . 38
5.4.1 Purpose . 38
5.4.2 Measuring circuit . 38
5.4.3 Principle of measurement . 39
5.4.4 Precautions during measurement . 40
5.4.5 Measurement procedures . 40
5.4.6 Specified conditions . 43
5.5 Frequency band . 43
5.5.1 Purpose . 43
5.5.2 Measuring circuit . 43
5.5.3 Principle of measurement . 45
5.5.4 Precautions during measurement . 47
5.5.5 Measurement procedure . 47
5.5.6 Specified conditions . 49
5.6 Resolution . 49
5.6.1 Purpose . 49

5.6.2 Measuring circuit . 49
5.6.3 Principle of measurement . 49
5.6.4 Measurement procedures . 50
5.6.5 Specified conditions . 51
Annex A (informative) Accuracy of measured value of gyro characteristics . 52
A.1 General . 52
A.2 Angle and angular rate . 52
A.3 Example of angular deviation occurring after calibration . 52
Bibliography . 53

Figure 1 – Example of measuring circuit . 11
Figure 2 – Example of wiring configuration . 12
Figure 3 – Example of measurement data when the angular rate is applied . 13
Figure 4 – Example of scale factor data at each temperature . 15
Figure 5 – Example of relationship between scale factor and scale factor temperature
coefficient at each temperature . 16
Figure 6 – Example of measurement of ratiometric error for the scale factor . 17
Figure 7 – Example measurement of scale factor stability . 19
Figure 8 – Example of measurement of scale factor symmetry . 20
Figure 9 – Measuring circuit for cross axis sensitivity . 25
Figure 10 – Principle of measurement for cross axis sensitivity . 26
Figure 11 – Measuring circuit 1 for bias . 29
Figure 12 – Measuring circuit 2 for bias . 30
Figure 13 – Example measurement of ratiometric error for bias . 32
Figure 14 – Bias temperature sensitivity and bias hysteresis. 34
Figure 15 – Bias linear acceleration sensitivity . 35
Figure 16 – Output noise measuring system . 39
Figure 17 – Example of wiring configuration for output noise. 39
Figure 18 – Frequency power spectrums. 40
Figure 19 – Angular random walk . 41
Figure 20 – Bias instability and Allan variance curve . 42
Figure 21 – Measuring circuit for frequency response . 44
Figure 22 – Example of wiring configuration for frequency response . 45
Figure 23 – Frequency response characteristics . 46
Figure 24 – Gain peak response characteristics . 46
Figure 25 – Calibration of frequency response . 48

Table 1 – Categories of gyro . 7
Table 2 – Absolute maximum ratings . 7
Table 3 – Normal operating ratings . 8
Table 4 – Characteristics . 9
Table 5 – Specified condition for measurement of scale factor . 23
Table 6 – Specified conditions for the measurement of bias . 37
Table 7 – Specified condition for the measurement of frequency band . 49
Table 8 – Specified condition for the measurement of resolution . 51

– 4 – IEC 62047-20:2014  IEC 2014
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SEMICONDUCTOR DEVICES –
MICRO-ELECTROMECHANICAL DEVICES –

Part 20: Gyroscopes
FOREWORD
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62047-20 has been prepared by subcommittee 47F: Micro-
electromechanical systems, of IEC 47: Semiconductor devices.
The text of this standard is based on the following documents:
FDIS Report on voting
47F/188/FDIS 47F/191/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

A list of all parts in the IEC 62047 series, published under the general title Semiconductor
devices – Micro-electromechanical devices, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 6 – IEC 62047-20:2014  IEC 2014
SEMICONDUCTOR DEVICES –
MICRO-ELECTROMECHANICAL DEVICES –

Part 20: Gyroscopes
1 Scope
This part of IEC 62047 specifies terms and definitions, ratings and characteristics, and
measuring methods of gyroscopes.
Gyroscopes are primarily used for consumer, general industries and aerospace applications.
MEMS and semiconductor lasers are widely used for device technology of gyroscopes.
Hereafter, gyroscope is referred to as gyro.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
None
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
rotating table
rate table
rotating tool on which a gyro is loaded during measurement
3.2
earth rate
angular rate generated in inertial space due to the rotation of the earth
Note 1 to entry: When the angular rate in inertial space is defined as stellar day 23 hours, 56 minutes, a
reference of 4,098 903 691 seconds is obtained as specified by the International Earth Rotation and Reference
Systems Service (IERS) and therefore, the angular rate of Earth in inertial space is approximately 15,04 °/h. For
details of the definition, refer to the IERS website (http://www.iers.org).
3.3
scale factor
ratio of gyro output voltage or output digital signal versus the rotating angular rate being
applied, described in unit: V/(°/s) or bit/(°/s )
4 Essential ratings and characteristics
4.1 Categorization of gyro
Table 1 shows uses of gyro categorized by application fields.

Table 1 – Categories of gyro
Category Contents
1 primarily for consumer use where variations of bias are not specified
2 primarily for industrial use where designing with appropriate range of values of
variations of bias
3 primarily for aerospace use where designing with detectable function of the earth
rate
4.2 Absolute maximum ratings
Table 2 describes absolute maximum ratings of gyro.
The following items listed in the table shall be described in the specification, unless otherwise
stated in the relevant procurement specifications. Stresses over these limits can be one of the
causes of permanent damage to the devices.
Table 2 – Absolute maximum ratings
Item no Absolute Category Specification Unit Remarks
maximum
1 2 3 min typ max
ratings
4.2.1 Storage x x x x x °C
temperature
range
4.2.2 Operating x x x x x °C
temperature
range
4.2.3 Storage    % Moisture absorption management level (for
humidity example, see levels specified in Table 5-1
range "Moisture Sensitivity Levels" of page 7 in
IPC/JEDEC J-STD-020C, [1] ) for reflow
soldering shall be specified. Those
descriptions shall not be provided to devices
applied with no reflow soldering process
and/or hermetic seal packaging process.
4.2.4 Mechanical x x x  x m/s Maximum limiting value of mechanical shock
shock in which does not cause permanent damage to
operating devices under an appropriate operating
state state. Acceleration, times and wave forms
shall be specified.
4.2.5 Mechanical x x x  x m/s Maximum limiting value of mechanical shock
shock in non which does not cause permanent damage to
operating devices under an appropriate non-operating
state state. Acceleration, times and wave forms
shall be specified.
4.2.6 Mechanical x x x  x m/s Maximum limiting value of mechanical

vibration in vibration acceleration and frequency which
operating does not cause permanent damage to
state devices under an appropriate operating
state.
4.2.7 Mechanical x x x  x m/s Maximum limiting value of mechanical

vibration in vibration acceleration and frequency which
non operating does not cause permanent damage to
state devices under an appropriate non-operating
state.
4.2.8 Angular rate x x x  x °/s Maximum limiting value of angular rate

limit which does not cause permanent damage to
devices under an appropriate operating
state.
______________
Numbers in square brackets refer to the Bibliography.

– 8 – IEC 62047-20:2014  IEC 2014
Item no Absolute Category Specification Unit Remarks
maximum
1 2 3 min typ max
ratings
4.2.9 Angular x x x  x °/s Maximum limiting value of angular

acceleration acceleration which does not cause
limit permanent damage to devices under an
appropriate operating state.
4.2.10 Maximum x x x  x V Maximum limiting value of supply voltage

supply which does not cause permanent damage to

voltage devices.
4.2.11 Maximum   x A Maximum limiting value of supply current

supply current which does not cause permanent damage to

devices. This limiting value shall be

specified only for a kind of constant current
driving devices.
NOTE x: mandatory, blank: optional

4.3 Normal operating rating
Table 3 describes normal operating ratings of gyro.
The following items should be described in the specification, unless otherwise stated in the
relevant procurement specifications. These conditions are recommended to keep specified
characteristics in stable state during operations of applying devices.
Table 3 – Normal operating ratings
Item no. Normal operating Category Specification Unit Remarks
ratings
1 2 3 min typ max
4.3.1 Guarantee operating x x x x x °C
temperature range
4.3.2 Guarantee operating x x x  x %
humidity range
4.3.3 Supply voltage range x x x x x x V
4.3.4 Current consumption x x x  x A
4.3.5 Start up current  x  x A
4.3.6 Power supply ripple  x  x Vpp
requirement
4.3.7 Other environmental  x x Recommended ranges of appropriate

condition indexes of environmental conditions
(such as conditions of
electromagnetic environments, air
pressure) specified as a specified
minimum value to maximum value.
4.3.8 Overload recovering  x  x s Maximum value of overload
time recovering time in the range of

measurement less than maximum
rating.
NOTE x: mandatory, blank: optional

4.4 Characteristics
Table 4 describes characteristics of gyro.

Table 4 – Characteristics
Item Characteristics Category Specification Unit Remarks
no
1 2 3 min typ max
4.4.1 Measurement x x x  x °/s Angular rate measuring range for

range guarantee of performance
4.4.2 Nominal scale x x x x V/(°/s) Nominal scale factor is also called as
factor
standard sensitivity.
or
bit/(°/s)
4.4.3 Initial scale x x x x % Minimum and maximum value of
factor variation variation from standard sensitivity at
a specified temperature
4.4.4 Scale factor x x x x % Minimum and maximum value of

variation with standard sensitivity under a specified
temperature or variation in temperature
Temperature
coefficient of
scale factor
4.4.5 Ratiometric error  x  x % Maximum value of error of sensitivity

for scale factor applying voltage fluctuation caused
by operating instability of applying
electric power supply
4.4.6 Linearity   x %
4.4.7 Scale factor n x x  A typical value of stability of

stability sensitivity under a specified definite
input voltage value
4.4.8 Scale factor n x x  A typical value of asymmetry of

symmetry sensitivity defined as a ratio of the
sensitivity applying plus value of a
specified input voltage to minus
value of a specified input voltage,
see 5.1.3.8.
4.4.9 Cross axis  x  x % Maximum value of sensitivity of cross

sensitivity axis (see 5.2.3 Principle of
measurement).
4.4.10 Nominal bias x x x x V or bit Typical value of bias voltage or bit

value under an appropriate applying
input voltage value
4.4.11 Initial bias  x x x °/s Minimum and maximum value of bias

variation under a specified temperature
4.4.12 Bias variation  x x x °/s Minimum and maximum value of

with temperature standard bias under a specified
or Temperature variation in temperature
coefficient of
bias
4.4.13 Ratiometric error  x  x V Maximum value of error of bias

for bias applying voltage fluctuation caused
by operating instability of applying
electric power supply. No description
is required for digital output case.
4.4.14 Bias repeatability  x x x °/s Minimum value and maximum value

(switch on to of bias fluctuation of each period
switch off) during a switching on state to a
switching off state
4.4.15 Bias hysteresis  x  x °/s Maximum value of hysteresis of bias

under a specified variation in
temperature
4.4.16 Linear g  x  x Maximum value of changed bias

sensitivity value under operating conditions of a
specified constant acceleration
value, expressed in comparison with
g((°/s)/g)
– 10 – IEC 62047-20:2014  IEC 2014
Item Characteristics Category Specification Unit Remarks
no
1 2 3 min typ max
4.4.17 Bias drift after  x  x °/s Maximum value of drift of bias during

power on turned on state of applying electric

power supply
4.4.18 In-band noise  x  x °/s In-band output noise at stable state

operation, described with RMS
4.4.19 Broadband noise  x  x °/s Broadband output noise at stable

state operation, described with RMS
o o
4.4.20 Angular random  x  x /√h or ( Output variation of gyroscope due to
walk /h)/√Hz noise, described with RMS
4.4.21 Bias instability  x  x °/s Described with RMS

4.4.22 Start up time  x  x s Time required for the gyro output to

reach the specified output after
power on
4.4.23 Frequency band x x x x  Hz Frequency response characteristics

4.4.24 Gain peak   x dB Maximum value of gain of frequency

characteristics under a specified

frequency. Describe with a specified
value of the frequency (Hz).
Detectable minimum change in the
4.4.25 Resolution x x °/s
input angular rate
NOTE x: mandatory, blank: optional, n: unnecessary

5 Measuring methods
5.1 Scale factor
5.1.1 Purpose
To specify measuring method relating to scale factor in gyro.
5.1.2 Measuring circuit (circuit diagram)
Figure 1 shows an example of composition of the sensitivity measuring circuit and Figure 2
shows an example of wiring configuration. The measuring circuit is composed of the gyro to
be measured and the devices listed below. Components to apply in the measuring circuit shall
satisfy the points described below.
– Temperature controlled chamber: This should be capable of maintaining the gyro at a
specified ambient temperature. Furthermore, the temperature control range should be
wider than the operating temperature range of gyro.
– Temperature sensor: This should be capable of measuring the temperature in the
temperature controlled chamber. A temperature sensor provided in advance in the
temperature controlled chamber can be used.
– Power supply for gyro: This should be capable of supplying the voltage and current
required by gyro. The fluctuating range for ripple voltage on the output should meet the
gyro requirements in the supplying state.
– Data acquisition system: Measuring device or measuring system adjusted to the output
configuration of gyro. For example, a digital multimeter or data logger is used if gyro
output is analogue voltage.
– Rotating table control device: Control device which controls the input angular rate given to
the rating table. This table is given an angular rate of rotation that is not less than the
detection range of gyro, and that is capable of accommodating changes in the angular rate
corresponding to the minimum resolution. See Annex A for measurement accuracy of the
rotating table.
– Measuring system controller: An overall system for automatic control of the power supply,
gyro, data acquisition system and rotating table control device. This is not required for
manual operation.
– Slip ring: It should be noted that the slip ring can be a source of noise generation.

IEC  2054/14
Key
1 DUT, a piece of gyro
2 rate table
3 temperature controlled chamber, to keep a specified temperature value of DUT
4 temperature sensor, to monitor environmental temperature in a chamber
5 power supply to operate DUT
6 data logger, to obtain data during the measurement
7 controller for rate table, to set up a specified rotating condition of the rate table
8 control system, to control the measuring circuit during the measurement
9 slip ring
Figure 1 – Example of measuring circuit

– 12 – IEC 62047-20:2014  IEC 2014
a
Vdd
Vdd monitor
DUT output
IEC  2055/14
Key
1 DUT, a piece of gyro
2 temperature controlled chamber, to keep a specified temperature value of DUT
3 thermometer, to monitor environmental temperature in a chamber
4 power supply, to supply electric power to operate DUT
5 monitor for power supply
6 data logger, to obtain data during the measurement
7 control system
8 slip ring position (when slip ring used)
a length from power supply feedback position to gyro supply terminal position (the length of wiring
should preferably be as short as possible)
Vdd voltage of power supply
Vdd Monitor
DUT output output of DUT (gyro)
Figure 2 – Example of wiring configuration
5.1.3 Measuring principle
5.1.3.1 Scale factor
In the measuring circuit shown in Figure 1, while gyro is under conditions of a specified
measuring temperature T (specified temperature provided as a medium value between a
BASE
specified minimum operating temperature and maximum operating temperature, see Figure 4)
and a specified supply voltage V , rotating angular rate of x , x , ---, x which divides
BASE 1 2 2n+1,
lower and higher half detection range of gyro into n-distribution such as x , x , ---, x
1 2 n
(preferably n ≥ 5) are applied, and corresponding output values of signal of y , y , ---, y
1 2 2n+1
measured in unit of V/(°/s) or bit/(°/s) of this detection input angular rate.

Furthermore, although the manufacturer can specify the value of n, it can be changed as
necessary based on specifications agreed between a manufacturer and its user.
Figure 3 shows an example of the measurement data. Abbreviated symbols of CCW and CW
in the figure show the left rotation (counter clockwise) and right rotation (clockwise),
respectively. (In Figure 3, it is equally divided by n = 5 and a total of 11 points of data are
shown including the stationary state). A scale factor is obtained by calculations from these
points. However, since acquired data are not on a straight line as represented by Figure 3, a
straight line on which the sum of squares becomes minimum is obtained by calculation (this
straight line is referred to hereafter as the best fit line).
y
2n+1
y
n+1
y 3 3
x x x
1 n+1 2n+1
X  (°/s)
IEC  2056/14
Key
1 points of measurement data at the applied angular rate value
2 best fit line
3 divided in specified intervals of “n”
X x-axis, input angular rate in unit of °/s
x CCW maximum detection
stationary state
x
n+1
x CW maximum detection input angular rate
2n+1
Y y-axis, gyro output signal in unit of V or bit
y CCW side maximum output value
y output value at stationary state
n+1
y CW side maximum output value
2n+1
Figure 3 – Example of measurement data when the angular rate is applied
” and the angular
Here, the gyro output value at each measuring point is represented by “y
i
rate to be input to gyro is represented by “x ”. Constants of the best fit line “y = a × x +
i BASE
b ” are then obtained as follows:
BASE
2n+1 2n+1 2n+1
(2n +1) x y − x y
∑ i i ∑ i ∑ i
i=1 i=1 i=1
a =
(1)
BASE
2n+1 2n+1
 
(2n +1) x −  x 
∑ i ∑ i
i=1  i=1 
Y  (V or bit)
– 14 – IEC 62047-20:2014  IEC 2014
+ + + +
2n 1 2n 1 2 n 1 2n 1
x y − x y x
∑ ∑ ∑ ∑
i i i i i
i= 1 i= 1 i= 1 i= 1
=
b
BASE 2
2n + 1 2n + 1
 
(2 n + 1) x −  x 
∑ ∑
i i
(2)
i= 1  i= 1 
Inclination “a ” of the best fit line on this occasion is the scale factor under the conditions
BASE
of reference measurement temperature “T ” and reference supply voltage “V ”.
BASE BASE
5.1.3.2 Initial scale factor variation
This shows the amount of variation between the scale factor “a ” and the nominal scale
BASE
factor (standard value of scale factor) “a ” of its gyro under the conditions of reference
TYP
measurement temperature “T ” and reference supply voltage “V ” of gyro.
BASE BASE
Here, initial scale factor variation “S ” is obtained as follows:
F,VAR,BASE
a − a
BASE TYP
SF,VAR, BASE =
(3)
a
TYP
5.1.3.3 Scale factor variation with temperature
When the operating temperature range of gyro into m-distribution of T , T , ----, T
1 2 m+1
(preferably m ≥ 4) under the condition of reference supply voltage “V ” of gyro, and the
BASE
scale factor obtained at each temperature values of "T , T , … T " is expressed by "ɑ , ɑ ,
1 2 m+1 T1 T2
… ɑ ", respectively, the amount of variation between these values and “ɑ ” represents
Tm+1 BASE
the temperature error at that temperature.
Furthermore, although the manufacturer can specify the value of m, it can be changed as
necessary based on specifications agreed between a manufacturer and its user.
Figure 4 shows an example of scale factor data. (In Figure 4, it is equally divided by m = 4
and one with m = 3 is considered to be the reference measurement temperature).

Y
a
T,m+1
a
BASE
a
T,1
T T T
BASE X
1 m+1
IEC  2057/14
Key
1 scale factor value at each temperature
2 divided in m-segments
X x-axis: gyro environment temperature
T lower operating temperature
T
reference measurement temperature
BASE
T maximum operating temperature
m+1
Y y-axis: gyro scale factor value
ɑ scale factor value at minimum operating temperature
T,1
ɑ scale factor value at reference measurement temperature
BASE
ɑ
scale factor value at maximum operating temperature
T,m+1
Figure 4 – Example of scale factor data at each temperature
Here, when the scale factor at temperature “T ” is represented by “a ”, the scale factor
i T,i
” is obtained as follows:
variation with temperature “S
F,VAR,Ti
a − a
T,i BASE
(4)
SF , VAR, Ti =
a
BASE
The above calculation is carried out for each of the temperatures "T , T , … T " and the
1 2 m+1
value “S ” obtained is the scale factor variation with temperature value at that
F,VAR,Ti
temperature “T ”.
i
5.1.3.4 Temperature coefficient for scale factor
The amount of inclination of temperature change for scale factor variation with temperature
under the condition of reference supply voltage “V ” of gyro becomes the temperature
BASE
coefficient for the scale factor. Figure 5 shows an example.

– 16 – IEC 62047-20:2014  IEC 2014
Y
a
T,m+1
a
BASE
a
T1 2
T T
T
X
1 BASE m+1
IEC  2058/14
Key
1 scale factor value at each temperature
2 divided in m-segments
3 best fit line (Temperature coefficient = T )
c,SF
X x-axis: gyro environment temperature
T
minimum operating temperature
T reference measurement temperature
BASE
T maximum operating temperature
m+1
Y y-axis: gyro scale factor value
a scale factor value at minimum operating temperature
T,1
a scale factor value at reference measurement temperature
BASE
a scale factor value at maximum operating temperature
T,m+1
Figure 5 – Example of relationship between scale factor and
scale factor temperature coefficient at each temperature
For "a , a , … a " obtained by the method shown in 5.1.3.3, the straight line, best fit
T,1 T,2 T,m+1
line “y = T × x + c” on which the sum of squares becomes minimum is obtained.
c,SF
m+1 m+1 m+1
( )
m +1 Ta − T a
∑ ∑ ∑
i Ti i Ti
i=1 i=1 i=1
T =
c, (5)
SF 2
m+1 m+1
 
(m +1) T −  T 
∑ i ∑ i
i=1  i=1 
m+1 m+1 m+1 m+1
T a − T a T
∑ ∑ ∑ ∑
i Ti i Ti i
i=1 i=1 i=1 i=1
c =
(6)
m+1 m+1
 
(m +1) T −  T 
∑ i ∑ i
i=1 i=1
 
Inclination T of the best fit line on this occasion is the temperature coefficient for the scale
c,SF
factor.
5.1.3.5 Ratiometric error for scale factor
When the operating power voltage range of gyro is divided in p-distribution (preferably p ≥ 2)
” of gyro, the scale factor at
under the condition of reference measurement temperature “T
BASE
each power voltage “V , V , … V ” becomes “a , a , …a ” respectively.
1 2 p+1 V,1 V,2 V,p+1
Here, although the manufacturer can specify the value of p, it can be changed as necessary
based on discussions between the user and manufacturer.
Figure 6 shows an example of ratiometric error for scale factor data. (In Figure 6, it is equally
divided by p = 2 and one with p = 2 is considered to be the reference supply voltage).
Y
a
V,p+1
a
BASE
a
V,1
V V
V
1 BASE X
p+1
IEC  2059/14
Key
1 ratiometric error amount (R )
error,v1
2 ratiometric error amount (R )
error,Vp+1
3 divided in p-segments
X x-axis: gyro operating voltage
V
operating voltage lower limit
V reference supply voltage
BASE
V operating voltage upper limit
p+1
Y y-axis: gyro scale factor value
a scale factor value at operating voltage lower limit
V,1
a
scale factor value at reference supply voltage
BASE
a scale factor value at operating voltage upper limit
Vp+1
Figure 6 – Example of measurement of ratiometric error for the scale factor
In this case, ratiometric error for the scale factor “R ” is obtained as follows:
error,Vi
 V 
i
 
a − (a )×
Vi BASE
 
V
 BASE  (7)
R =
error,Vi
a
BASE
The above-shown calculation is carried out for each of voltages “V , V , … V ” and the
1 2 p+1
value “R ” obtained is the ratiometric error for the scale factor value at the voltage “V ”.
error,Vi i
– 18 – IEC 62047-20:201
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