SCA121T Series
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THE SCA121T DUAL AXIS INCLINOM ETER MODULES
The SCA 121T Series contain 3D-MEMS-based du al ax is inclinometer modules that provide instrumentatio n grade
performance for leveling applications in harsh environment. The measuring axes of the sensing elements are
parallel to the mounting plane and orthogonal to each other. Low temperature dependency, high resolution and
low noise, together a with robust sensing element design, make the SCA121T the ideal choice for leveling
instruments. The Murata inclinometers are insensitive to vibration, due to their over damped sensing elements,
and can withstand mechanical shocks of up to 20000 g .
Features
• Dual axis inclination measurement (X and Y)
• Measuring ranges ±30° and ± 90°
• 0.0025° resolution (10 Hz BW, analog output)
• Sensing element controlled over damped
frequency response (-3d B 18H z)
• Robust design, high shock durability (20000g)
• High stability over temperature and time
• Single +5 V supply and unregulated 7…35V
supply
• RoHS compliant
Applications
• Platform leveling and stabilization
• 360° vertical orientation measurement
• Leveling instruments
• Constructi on le vels
Data Sheet
SCA121T Series
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TABLE OF CONTENTS
The SCA121T Dual Axis Inclinometer modules ..................................................................... 1
Features............................................................................................................................................. 1
Applications ...................................................................................................................................... 1
Table of Contents...................................................................................................................... 2
1 Electri cal Sp ec i fi cat i o ns ..................................................................................................... 3
1.1 Ab sol ut e M aximum Ratings ................................................................................................... 3
1.2 Performance Characteristics .................................................................................................. 3
1.3 Electrical Characteristics ....................................................................................................... 4
1.4 Electrical Connection.............................................................................................................. 4
2 Functional Description ....................................................................................................... 4
2.1 Measuring Directions .............................................................................................................. 4
2.2 Voltage to A ngle Conversion ................................................................................................. 4
2.3 Ratiometric Output .................................................................................................................. 5
3 Mechanical Specifications .................................................................................................. 5
3.1 Sensor dimensions ................................................................................................................. 5
SCA121T Series
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1 Electrical Specifications
The SCA 121T pr o duc t f amily c omprises t hree vers io ns, the S CA 121T-D03, the S CA121T-D05 and
the SCA121T-D07 that differs in measurement range and supply voltage. The product version
specific performance specifications are listed in the table SCA121T performance characteristics
below.
1.1 Absolute Maximum Ratings
Suppl y voltage SCA121T-D05(V
DD
)
Supply voltage SCA121T-D03 and D07
Voltage at input / output pins
Storage temperature
Operating temperature
Mechanical shock
Regulated -0.3 V to +5.5V
Unregulated -0.3 V to +35V
-0.3V to 5.3
-55°C to +125°C
-40°C to +125°C
Drop from 1 meter onto a concrete surface
(20000g). Powered or non-powered
1.2 Performance Characteristics
Parameter Condition SCA121T-
D03
SCA121T
-D05
SCA121T
-D07
Units
Measuring range Nominal ±90
±1
±90
±1
±30
±0.5
°
g
Suppl y Voltage
7…35
5±0.25
7…35
V
Offset (Output at 0g)
2.5
Vdd/2
2.5
V
Offset calibration error
Max deviation
±1.5
±1.5
±1.5
°
Sensitivity
between 0…1 °
(1
2
35
2
35
4
70
V/g
mV/°
Sensitivity calibration
error
±1.5 ±1.5 ±1.5 %
Offset temperature
dependency
-25…85°C
±1
±1
±1
°
0…70°C
±0.5
±0.5
±0.5
°
Sensitivity temperature
dependency
-25...85°C
-1.5...+0.5
-1.5...+0.5
-1.5...+0.5
%
0…70°C
-0.8...+0.3
-0.8...+0.3
-0.8...+0.3
%
Typical non-linearity
Measuring range
±0.57
±0.57
±0.11
°
Frequency response –3dB LP
(2
8-28 8-28 8-28 Hz
Ratiometric error
Vdd = 4.75...5.25 V
±1
%
Cross-axis sensitivity
Max.
4
4
%
Note 1. The angle output has SIN curve relationship to voltage out put
Note 2. The frequency response is determined by the sensing el em ent’s i nternal gas damping.
SCA121T Series
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1.3 Electrical Characteristics
Parameter
Condition
Min.
Typ
Max.
Units
Current consumption
Vdd = 5 V; No load
5
8
mA
Operating temperature
-25
+85
°C
Analo g resisti ve out put lo a d
Vout to Vdd or GND
10
kOhm
Analog capac iti ve out put lo ad
Vout to Vdd or GND
20
nF
Start-up delay
Reset and parity check
10
ms
1.4 Electrical Connection
Wire Color
Name
Function
Blue
GND
Ground
Red
Vdd
Power supply
Yellow
Out X
X-axis output
Green
Out Y
Y-axis output
White
NC
Not Connected
2 Functional Description
2.1 Measuring Directions
Figure 1. The measuring directions of the SCA121T
2.2 Voltage to Angle Conversion
Analog output can be transferred to angle using the following equation for conversion:
−
=ySensitivit
OffsetVout
arcsin
α
Where: Offset = output of the device at 0° inclination position, Sensitivity is the sensitivity of the
device and V Dout is the output of the SCA121T. T he nominal off set is 2.5 V an d the sensiti vity is 4
V/g for the SCA121T-D07 and 2 V/g for the SCA121T-D03 and SCA121T-D05.
Angles cl os e t o 0 ° incli nat io n c an be est im at ed q uit e a cc ur atel y with s tr a igh t l ine c onvers i on but f or
the best possible accuracy, arcsine conversion is recommended to be used. The following table
shows the angle measurement error if straight line conversion is used.
SCA121T Series
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ySensitivit
OffsetV
out
−
=
α
Straight line co nv ers ion eq uati on:
Where: Sensitivity = 70mV/° with SCA121T-D07 or Sensitivity= 35mV/° with SCA121T-D03 and
SCA121T-D05
Tilt angle [°]
Straight line conversion error [°]
0
0
1
0.0027
2
0.0058
3
0.0094
4
0.0140
5
0.0198
10
0.0787
15
0.2185
30
1.668
2.3 Ratiometric Output
Ratiom etric output m eans that the zero of fs et point a nd s ensiti vit y of the se nsor are pr oportio nal to
the suppl y voltage. If the S CA121T-D05 supp ly voltag e is fluctu ating the SCA121T-D05 output will
also vary. When the same reference voltage for both the SCA121T-D05 sensor module and the
measuring part (A/D-converter) is used, the error caused by reference voltage variation is
automatically compensated for.
3 Mechanical Specifications
Cable length: -D03,-D07 30cm
-D05 110cm
Cable type: UL/CSA liste d, PUR blac k
Cable diam.: 6±0.2mm
Leads: 5 x 0.14mm2
Total weight: Approx. 60 grams
Protection class: IP66
Housing: Zinc cast ing w ith pass ivati o n
Mounting: The sensor module is to be mounted on a flat and smooth surface
with 2 screws, dimension M4. Mounting torque 5 ±1Nm
3.1 Sensor dimensions
Figure 2. Mechanical dimensions of the SCA121T (Dimensions in mm)
