The IT Law Wiki



A sensor is

[h]ardware found on a biometric device that converts biometric input into a digital signal and conveys this information to the processing device.[1]


A sensor

[is a] peripheral input device which senses some variable in the system environment, such as temperature, and converts it to an electrical signal which can be further converted to a digital signal for processing by the computer.[2]
[c]onverts a pressure, temperature, or other physical parameter into an electrical signal, often for use in a control system.[3]
[is] equipment which detects, and may indicate, and/or record objects and activities by means of energy or particles emitted, reflected, or modified by objects. Note. The energy may be nuclear, electromagnetic, including the visible and invisible portions of the spectrum, chemical, biological, thermal or mechanical, including sound, blast and earth vibration.[4]
[is a] device that produces a voltage or current output that is representative of some physical property being measured (e.g., speed, temperature, flow).[5]
is a special device that perceives certain characteristics of the real world and transfers them into a digital representation.[6]

Internet of Things[]

A sensor is

an electronic utility (eUtility) that measures physical properties such as temperature, acceleration, weight, sound, location, presence, identity, etc. All sensors employ mechanical, electrical, chemical, optical, or other effects at an interface to a controlled process or open environment.[7]
[a] portion of an IoT device capable of providing an observation of an aspect of the physical world in the form of measurement data.[8]


Sensors are a type of electronic device that must produce the miniscule amount of power required to convey information at a usable error rate. Sound, light, atmospheric conditions, vibrations, and other environmental signals are all fair game for sensor designers.

Basic properties, assumptions, recommendations, and general statements about sensors include:

1. Sensors are physical; some may have an Internet access capability.
2. Sensor output is data; . . . Analog sensors such as microphones and voltmeters are counterexamples.
3. A sensor may also transmit device identification information, such as via Radio Frequency Identification (RFID).
4. Sensors may have an identity or have the identity of the "thing" to which they are attached.
5. Sensors may have little or no software functionality and computing power; more advanced sensors may have software functionality and computing power.
6. Sensors may be heterogeneous, from different manufacturers, and collect data, with varying levels of data integrity.
7. Sensors may be associated with fixed geographic locations or may be mobile.
8. Sensors may provide surveillance. Cameras and microphones are sensors.
9. Sensors may have an owner(s) who will have control of the data their sensors collect, who is allowed to access it, and when.
10. Sensors will have pedigree — geographic locations of origin and manufacturers. Pedigree may be unknown, and suspect.
11. Sensors may be cheap, disposable, and susceptible to wear-out over time.
12. There may be differentials in sensor security, safety, and reliability, e.g., between consumer grade, military grade, industrial grade, etc.
13. Sensors may return no data, totally flawed data, partially flawed data, or correct and acceptable data. Sensors may fail completely or intermittently. They may lose sensitivity or calibration.
14. Sensors are expected to return data in certain ranges, e.g., [1 ... 100]. When ranges are violated, rules may be needed on whether to turn control over to a human or machine when ignoring out-of-bounds data is inappropriate.
15. Sensors may be disposable or serviceable in terms of calibration, sensitivity or other forms of refresh. Complex and expensive sensors may be repaired instead of replaced.
16. Sensors may be powered in a variety of ways including alternating current (AC), solar, wind, battery, or passively via radio waves.
17. Sensors may be acquired off-the-shelf or built to specification.
18. Sensors acquire data that can be event-driven, driven by manual input, command-driven, or released at pre-defined times.
19. Sensors may have a level of data integrity ascribed.
20. Sensors may have their data encrypted to void some security concerns.
21. Sensors should have the capability to be authenticated as genuine.
22. Sensor data may be sent and communicated to multiple NoTs. A sensor may have multiple recipients of its data. Sensor data may be leased to one or more NoTs.
23. The frequency with which sensors release data impacts the data's currency and relevance. Sensors may return valid but stale data. Sensor data may be "at rest" for long periods of time.
24. A sensor's precision may determine how much information is provided. Uncertainty of sensor data should be considered.
25. Sensors may transmit data about the "health" of a system, such as is done in prognostics and health management (PHM).
26. * * * When classified as an eUtility, humans can still act in a sensor-like role by manually feeding data into a NoT's workflow and data flow.
27. Humans can influence sensor performance through failure to follow policy, sensor misplacement, etc. (or their positive analogs). Humans are potential contributors to sensor failures.
28. Security is a concern for sensors if they or their data is tampered with, stolen, deleted, dropped, or transmitted insecurely so it can be accessed by unauthorized parties. Building security into specific sensors may or may not be necessary based on the overall system design.
29. Reliability is a concern for sensors.


  1. Biometrics Identity Management Agency, Biometrics Glossary, at 55 (Ver. 5) (Oct. 2010) (full-text).
  2. U.S. Food and Drug Administration, Glossary of Computerized System and Software Development Technology 26 (Aug. 1995) (full-text).
  3. Miniaturization Technologies, App. B, Glossary, at 44.
  4. Glossary of Communication Electronic Terms, at 2-136.
  5. NIST Special Publication 800-82, at B-7.
  6. Framework for Cyber-Physical Systems, at 17.
  7. NIST Special Publication 800-183, at 2.
  8. Foundational Cybersecurity Activities for IoT Device Manufacturers, at 27.


See also[]