The document discusses wireless telemetry systems for measuring torque. It describes the evolution of torque measurement technologies including phase shift, optical, and strain gage methods. Wireless telemetry offers advantages like reduced costs, real-time data, and ability to measure things in dangerous places or that move. Key components of wireless telemetry systems include sensors, transmitters at the measurement end, receivers, and computers to process and store data at the receiving end. Common wireless applications are also discussed.

1. Basics of Wireless Rotary Torque
An Introduction to Digital Telemetry
Torque Measurement.

2. Evolution of Torque Measurement
Technology
• Measurement
o Phase Shift
o Optical
o Magnitostrictive
o Strain Gage
• Data Handling
o Slip Ring
o Rotary Transformer
o Wireless • Wireless
o Telemetry
o RF
o Blue Tooth (BT400)

3. Advantages of Wireless Telemetry
Wireless telemetry can help you sleep at night. It lets you…
• Greatly reduce operational costs
o If your vending machines had wireless telemetry they
could automatically tell you when to restock.
• Get now-time (real time) information
o Telemetry Nursing is a rapidly growing area of enhanced
patient care.
• Get data from things that move.
• Easily incorporate data into other systems
o Domestic electricity meters may be telemetered and the
measured amount of electrical power used at each
location automatically fed into a database, ready for
billing.

4. Advantages of Wireless Telemetry
(continued)
• Measure things in dangerous places.
o This may be routine monitoring around a nuclear
power station.
• Measure things that may be destroyed.
• Have confidence that the measurement are happening.
• No need for cables.

5. Are There Any Disadvantages?
Yes, but they are usually outweighed by the advantages
• Some initial equipment cost.
• Need a reliable wireless link; good radio contact
between transceivers.
• Some difficulty in exciting the sensor with on board
electronics (batteries???).

6. Wireless Telemetry Systems
A wireless telemetry system refers to the equipment you need
to allow measurements to be taken from one place and
transmitted to another place, where they are needed.
The most basic wireless telemetry system has a…
• Measuring end
• Receiving end

7. Wireless Telemetry Systems (continued)
At The Measuring End…
One commonly have two things:
• A sensor to sense the phenomena, such as strain,
temperature, etc.
• A wireless transmitter to send the measurement data
to the receiving end.
Most common use is that of a single wireless sensor (link).
However, one can connect more sensors to a data
storage device, such as a data logger. Data is then
transmitted from the logger, rather than directly from the
sensors.

8. Wireless Telemetry Systems (continued)
At The Receiving End…
• A wireless receiver to receive the measurement data
sent by the transmitter from the measurement end,
and…
• Something such as a computer, to process and store
the measurement information.
Wireless transmitters and receivers usually involve radio,
though not always. Some may involve electromagnetic
waves from a different part of the spectrum, such as light,
or microwaves. Or rarely, use sound waves in air or water.
These are pressure waves, generated by vibrating the air or
water and are quite different from electromagnetic waves.

9. FCC Rules for Unlicensed Wireless
Equipment Operating in the ISM Bands
The ISM radio bands were originally set aside for electromagnetic radiation
produced by industrial, scientific and medical (ISM) equipment. In the
early 1990's the Federal Communications Commission (FCC) allowed using
three of the ISM bands for unlicensed communication equipment. These
three ISM bands are:
• 902 to 928 MHz (6.78 MHz)
• 2.400 to 2.4835 GHz
• 5.725 to 5.875 GHz
Commercial usage
• Wireless LAN devices use wavebands as follows:
• Bluetooth 2450 MHz band
• HIPERLAN 5800 MHz band
• IEEE 802.11 2450 MHz and 5800 MHz bands
 IEEE 802.15.4 personal area networks may use the 915 MHz and
2450 MHz ISM bands.

10. Typical Wireless Applications

11. Wireless Flange Torque Measurement
Current Technology

12. BT 400 Prototype

13. Wireless Flange Torque
Measurement (continued)
State of the Art

14. Wireless Flange Torque Measurement
(continued)
Mounting Options
Floor Mount
Wall Mount
No caliper to align to antenna
No effect from nearby metal objects

15. Wall Mount Scenario
1-

16. Wall Mount Scenario
2-

17. Wall Mount Scenario
3-

18. Wall Mount Scenario
4-

19. BT400 Block Diagram
SENSOR INTELLIGENCE
SPECS:
USB
1 KHz
2 Hz
±5 VDC
±10 VDC
4 : 12 : 20 mA
WIRELESS LINK
PACKET DESCRIPTION:
(PACKET=BYTES)
H D D CS F
H=HEADER
D=DATA
CS=CHECKSUM
F=FOOTER
ACCURACY RESOLUTION
12K SPS << 3K READINGS/SEC.
16-BIT A/D << RESOLUTION
BAUD RATE: 230K

20. BAUD RATE: 230K
Definitions
SENSOR INTELLIGENCE
WIRELESS LINK
PACKET DESCRIPTION:
(PACKET=BYTES)
H D D CS F
H=HEADER
D=DATA
CS=CHECKSUM
F=FOOTER
FREQUENCY RESPONSE FREQUENCY RESPONSE
PHENOMENA WIRELESS
FREQUENCY
SPECS:
USB
1 KHz
2 Hz
±5 VDC
±10 VDC
4 : 12 : 20 mA
16-BIT A/D <<12K SPS << 3K READINGS/SEC.0.05% ORO
ANTI-ALIASING FILTERNATURAL FREQUENCY
ACCURACY
BAUD RATE
RESOLUTION
SPS/RPS

21. Definitions
• Sampling: the reduction of a continuous signal to a
discrete signal.
An ideal (theoretical) sampler is one that produces
samples equivalent to the instantaneous value of the
continuous signal at the desired points.
• Nyquest Sampling Rate: band limited signals can be
perfectly reconstructed from their samples if the
sampling rate is more than twice the maximum
frequency.
• Nyquist Frequency fN: is the highest signal frequency
that can be reconstructed from a certain sampling rate,
usually no higher than half the sampling rate.

22. Definitions (continued)
• Aliasing: for a function f with frequency f > fN , f
cannot be distinguished from other functions with
frequencies; nfN +f and nfN - f.
• Resolution of an A/D Converter: the smallest
voltage difference that can be detected. Also referred
to as the least significant bit (LSB) in the conversion.
• Quantization Error: quantization error results in
when an analogue signal is represented by a series of
discrete steps differing by the resolution of the
digitizing process.
ANTI-ALISING FILTER

23. Current vs. State of the Art Technology
Power
6.78 MHz
0.10 MHz
Distance
0.25”
35’ (60’ Line of Site)
500’ (1500’ Line of Site-RF)
Frequency
6.78 MHz
2450 MHz (Blue Tooth Channel)

24. Alternative Scenario
PACKET DESCRIPTION:
(PACKET=BYTES)
H D D CS F
H=HEADER
D=DATA
CS=CHECKSUM
F=FOOTER

25. Other Wireless Applications by
SensorData

26. Other Wireless Applications by
SensorData (continued)

27. Other Wireless Applications by
SensorData (continued)

28. Other Wireless Applications by
SensorData (continued)

29. Other Wireless Applications by
SensorData (continued)

30. Thank You