WATSON INDUSTRIES ADS-C232-1A User manual

Dual Axis Vertical Reference System
Owner’s Manual
ADS
-
C232
-
1A
Watson Industries, Inc.
3035 Melby Street
Eau Claire, WI 54703
P: 715 839 0628
F: 715 839 8248
E: [email protected]

Watson Industries, Inc. ADS-C232-1A Rev G 04/24/2023
2
Table of Contents
Introduction ................................................................................................................... 3
Product Description ...................................................................................................... 3
Installation .................................................................................................................... 3
Orientation: .................................................................................................................................................................... 3
Mounting:....................................................................................................................................................................... 3
Environment: ................................................................................................................................................................. 3
Power: ............................................................................................................................................................................ 4
Theory of Operation ..................................................................................................... 4
Specifications ................................................................................................................ 5
Analog Output .............................................................................................................. 5
Connections .................................................................................................................. 5
Dimensions ................................................................................................................... 6
WARNING ................................................................................................................... 7
Customer Service .......................................................................................................... 8
Watson Industries prides itself on solving customer problems and serving their needs in a timely fashion. This manual
is intended to facilitate this goal and to provide written information about your product. We ask that you carefully read
this manual. Becoming familiar with the manual will help you understand the product’s capabilities and limitations, as
well as provide you with a basic understanding of its operation. If, after reading the manual, you require further
assistance, do not hesitate to call Watson Industries with your questions and comments.
CAUTION!
Watson Sensors are rugged devices that have been used successfully in a number of harsh
environments. The components have been qualified to withstand a mechanical shock of 500g 's
and most enclosures provide near that level of protection. However, dropping a sensor from waist
height onto a hard floor can cause a shock level of 600g's. At this level, given some resonance,
damage is possible.

Watson Industries, Inc. ADS-C232-1A Rev G 04/24/2023
3
Introduction
The Watson Industries Vertical Reference represents a significant advancement in inertial sensor
technology. It is a highly accurate and rugged device with many advantages over other types of
angular rate and incline-sensing devices. This manual describes operation of the Watson Industries
Vertical Reference and also provides useful application information to the system designer.
Product Description
The Watson Industries Vertical Reference (ADS) is an entirely solid-state sensor that provides
exceptional rejection from the adverse effects of inertia and short-term lateral accelerations. It does
this through the use of both a pendulous vertical reference and an angular rate sensor that is
integrated to provide additional information on angular position. It can be a functional replacement
for mechanical gyros which are often more expensive and which cannot provide the reliability of a
solid-state sensor. Theory of operation is described with more detail on page 4. Size and pinouts
are described on pages 5-6. Specifications are shown on page 5.
The Watson Vertical References provide for two types of analog output voltages. One is
proportional to angular rate and the other is proportional to angular displacement. Full-scale
analog outputs produce an output of ±10 volts dependent upon the direction of angular position or
rotation. During rotation, positive voltage output occurs in the direction of the rotational arrow on
the case. At horizontal and zero angular rotation rate, both outputs for displacement and rotation
rate are near zero. A dual power supply, providing a regulated ±15 Volts DC, is required to operate
the unit.
Special options in power supply, output voltage, scale calibration, and special packaging are
available as custom units. Pricing and delivery information on custom units is available by
contacting the factory.
Installation
Orientation:
The base plate of the unit is to be mounted on top of a horizontal surface with rotation stickers
aligned with the attitude angles to be measured. The ADS drawing is located in Figure 2. The
ADS is a rugged device and will withstand harsh environments. However, due attention needs to be
paid to the nature of the sensor and its prime function, which is to measure attitude and motion.
Mounting:
The unit has four 0.15” diameter mounting holes for using 6-32 screws. A mounting plate is
provided for a flat surface mount. The unit may be adhesively mounted at any of its surfaces. If
high shock loads are expected, greater than 100G or repeated shocks greater than 20G, the
appropriate shock mounting should be used to prevent damage. Vibration environments would also
require shock mounts or vibration isolation.
Environment:
Avoid mounting sites that are subject to significant temperature variation over the duration of the
test. Temperature variation will induce significant rate sensor bias drift, which will reflect in poor
attitude accuracy.

Watson Industries, Inc. ADS-C232-1A Rev G 04/24/2023
4
For shipboard applications, install the sensor near the center of gravity. For all applications, it is
preferable to install the device where linear dynamic effects are minimized.
Power:
The unit requires a regulated ±15 VDC dual power supply (0.6 Watts). STABLE POWER IS
REQUIRED. The system is sensitive to power supply changes.
Theory of Operation
In order to obtain an accurate signal in both the short-term and in the long-term, the Vertical
Reference relies upon an Angular rate sensor combined with a solid-state pendulum. Integrating
the angular rate output generates the position output. This signal is compared with the output from
the pendulum and the resultant error signal is passed through a long time constant filter and fed
back as a bias to the rate sensor. Sending a portion of the error directly to the position integrator
damps the system. By using a long time constant, the effect of the short-term errors in the
pendulum is minimized. Thus, the adverse effects of inertia, damping and short-term lateral
accelerations on the pendulum essentially do not show up on the vertical reference output. See
Figure 1 for system overview.
The solid-state angular rate sensor has a sensing mechanism consisting of a piezoelectric transducer
element in a “tuning fork” configuration. The two drive elements are resonantly driven in opposite
directions. When a rotation occurs, the momentum stored in the vibrating elements causes an out-
of-plane bending force that is demodulated to accurately depict the rotation rate.
Since the output of the vertical reference involves the synchronizing of an integrator to a reference,
a rotation exceeding either the full scale limits of displacement or angular rate could greatly disturb
the synchronization and produce large errors. Returning the unit to a displacement and angular rate
within range would allow the unit to again synchronize. Depending on the extent of output
saturation, the synchronization will occur in less than sixty (60) seconds.
Figure 1

Watson Industries, Inc. ADS-C232-1A Rev G 04/24/2023
5
Specifications
Attitude
Range: X, Y axis
±30°
Analog Scale Factor:
3°/V
±10V Output
Accuracy: Static
±0.3°
*
Accuracy: Dynamic
2%
Angular Rate
Range: X, Y axis
±100°/sec
Resolution:
0.1°/sec
Analog Sca
le
Factor:
10°
/sec/V
±10V Output
Scale Factor Accuracy:
1%
Constant temperature
Bias: X, Y axis
< 1.5°/sec
Non
-
Linearity:
< 0.05%
Full scale range
Bandwidth:
50 Hz
Environmental
Temperature: Operating
-
20°C to +50°C
Temperature: Storage
-
30°
C to +60°C
Vibr
ation: Operating
2.5g rms
20 Hz to 2 KHz
Vibration: Survival
10g rms
20 Hz to 2 KHz
Shock: Survival
500g
10mS ½ sine wave
Electrical
Input Power: Positive
12 to 16VDC
0.3W
Input Power: Negative
-
12 to
-
16VDC
0.02W
Input Curr
e
nt:
25mA @ ±15VDC
Analog Output:
±10VDC
Analog Output Impedance:
300 Ohm
Physical
Axis Alignment:
< 2°
Size: Including Mounting Flanges
3.13"W x 4.5"L x 3.12"H
8.0 x 11.4 x 7.9 (cm)
Weight:
10.9 oz (0.7lb)
310 grams (0.3Kg)
Connection:
9
pin male "D" subminia
ture
*
Actual accuracy can be calculated as the listed percentage multiplied by the change in value over the entire dynamic maneuver.

Specifications are subject to chan
ge without notice.

This product may
be subject to export rest
ri
ctions. Export Classification ECCN 7A994.
Analog Output
The analog outputs can be found on the 9-pin male D-Sub connector. The analog outputs include:
Signal
Pin
Range
Output Range
0 VDC
Sca
le Factor
X Angle Displacement 6 
3
0

±10V 0° 3°/V
Y Angle Displacement 7 
30

±10V 0° 3°/V
X Angular Rate 8 
100

/s
±10V 0° 10°/V
Y Angular Rate 9 
100

/s
±10V 0° 10°/V
Connections
9
–
Pin Male Connector
Pin
Description
1
Power Ground
2
+15 VDC
3
No Connection
4
No Connection
5
-
15 VDC
6
X Angle Displa
ce
ment Analog Output
7
Y Angle Displacement Analog Output
8
X Angular Rate Analog Output
9
Y Angular Rate Analog
Output
The analog output connections are referenced to Ground on pin 1.

Watson Industries, Inc. ADS-C232-1A Rev G 04/24/2023
6
Dimensions
Figure 2: Dual Axis ADS-C232-1A
HANDLE WITH CARE
DELICATE INSTRUMENT
CAUTION
WATSON INDUSTRIES, INC.
www.watson-gyro.com
MADE IN U.S.A
P/N
REV
PWR
S/F
S/N:

Watson Industries, Inc. ADS-C232-1A Rev G 04/24/2023
7
WARNING
Rough handling or dropping of this unit is likely to cause damage.
Over-voltage and/or miswiring of this unit will cause damage.
This unit should be protected against prolonged exposure to high humidity and/or
salt air environments.
DISCLAIMER
The information contained in this manual is believed to be accurate and reliable; however, it is the
user’s responsibility to test and to determine whether a Watson Industries’ product is suitable for a
particular use.
Suggestion of uses should not be taken as inducements to infringe upon any patents.
WARRANTY
Watson Industries, Inc. warrants, to the original purchaser, this product to be free from defective
material or workmanship for a period of one full year from the date of purchase. Watson
Industries’ liability under this warranty is limited to repairing or replacing, at Watson Industries’
sole discretion, the defective product when returned to the factory, shipping charges prepaid, within
one full year from the date of purchase. The warranty described in this paragraph shall be in lieu of
any other warranty, express or implied, including but not limited to any implied warranty of
merchantability or fitness for a particular purpose.
Excluded from any warranty given by Watson Industries are products that have been subject to
abuse, misuse, damage or accident; that have been connected, installed or adjusted contrary to the
instructions furnished by seller; or that have been repaired by persons not authorized by Watson
Industries.
Watson Industries reserves the right to discontinue models, to change specifications, price or
design of this product at any time without notice and without incurring any obligation whatsoever.
The purchaser agrees to assume all liabilities for any damages and/or bodily injury that may result
from the use, or misuse, of this product by the purchaser, his employees or agents. The purchaser
further agrees that seller shall not be liable in any way for consequential damages resulting from
the use of this product.
No agent or representative of Watson Industries is authorized to assume, and Watson Industries
will not be bound by any other obligation or representation made in connection with the sale and/or
purchase of this product.
PRODUCT LIFE
The maximum expected life of this product is 20 years from the date of purchase. Watson
Industries, Inc. recommends the replacement of any product that has exceeded the product life
expectation.

Watson Industries, Inc. ADS-C232-1A Rev G 04/24/2023
8
Customer Service
All repairs, calibrations and upgrades are performed at the factory. Before returning any product,
please contact Watson Industries to obtain a Returned Material Authorization number (RMA).
Return Address & Contact Information
Watson Industries, Inc.
3035 Melby Street
Eau Claire, WI 54703
ATTN: Service Department
Telephone: [phone] Fax: [phone] email: [e-mail]
Returning the Product
Product shall be packaged making sure there is adequate packing around all sides. Correspondence shall
include:
 Customer’s Name and Address
 Contact Information
 Equipment Model Number
 Equipment Serial Number
 Description of Fault
It is the customer’s responsibility to pay all shipping charges from customer to Watson
Industries, including import and transportation charges.