A biometric trait must be reliable to be a useful security tool. This article begins with an overview of the seven characteristics used to compare the reliability of biometric traits. It then looks at how well some common biometric traits satisfy those requirements. It considers how multimodal authentication and sensor fusion can enhance security and […]
FAQ
What sensors indicate the weather: part 1
Temperature, barometric pressure, humidity, wind speed and direction, and possible rainfall (or snowfall) in specific areas are common indicators of current and future weather conditions. However, other sensor inputs, such as pressure drop, air quality, particulate matter (including dust), and more (storm surge), are frequently required to identify and react to extreme weather conditions. The recent hurricanes […]
What determines the connectivity bandwidth needed in a machine vision system?
This article reviews resolution, definition, frame rate, and bit depth and how they impact connectivity bandwidth requirements. It then looks at a practical example of the requirements for an effective automotive pedestrian imaging system, including the importance of the Johnson criteria for night vision. Pixels, their sizes, numbers, and composition are the bedrock upon which […]
Does TPMS need a pressure sensor?
It seems obvious that a Tire Pressure Monitoring System (TPMS), required by several governments, would need a pressure sensor. But that’s not true. Alternative approaches take advantage of other sensing capabilities in a vehicle, computing, and algorithms to implement a solution for TPMS that meets legislated requirements. The alternative, indirect, approach has been used for […]
What are magnetic rotary encoders?
Part 1 of this FAQ looked at the optical rotary encoder, a low-cost, high-resolution, easy-to-use sensor for indicating incremental shaft position (although it can be “upgraded” to indicate absolute position as well). Q: What is the basic principle of the magnetic encoder? A: The magnetic encoder uses a rotating gear made of ferrous metal, and […]
What are optical rotary encoders?
Accurate measurement of rotary shaft motion, including position, velocity, and acceleration, is crucial in numerous applications. This is typically achieved by incorporating a rotary encoder into the motor or shaft assembly. While “rotary encoder” is often abbreviated to “encoder,” it should not be confused with other electromechanical or electronic encoding devices used for data format […]
FAQ on thermistors for temperature sensing
The thermistor is a widely used temperature sensor and an attractive alternative to thermocouples and RTDs — but only in some applications. Temperature is the most commonly assessed and measured physical parameter; if you add all the consumer, industrial, commercial, medical, food-related, product tests and measurements, and other places where it needs to be sensed. […]
Sensors in American football can help the game
By Anson Yeganegi and Song Li, InvenSense, a TDK company Sensors can improve player safety and performance through data collection. Both soccer and American football have embraced advanced technologies to varying degrees, including the use of sensors to elevate tracking and data collection in both games. For instance, the first sensor-enabled game ball using Connected […]
What sensors are used in pizza ovens and prep areas?
Sensors monitor the temperature of pizza ovens and preparation (prep) areas. They also monitor and control the speed of pizza movement in conveyor ovens. A variety of sensor technologies are used in specific types of pizza ovens and for specific purposes. This article briefly reviews the U.S. Food and Drug Administration (FDA) Food Safety Modernization […]
What are the types and uses of position and angle sensors in an EV?
Position and angle sensors are used in several electric vehicle (EV) components, including the traction motor and drivetrain, heating, ventilation, air-conditioning (HVAC) compressor, steer-by-wire, brake-by-wire, regenerative braking, accelerator position, active headlight aiming, active suspension systems, and more. This FAQ reviews some position and angle sensing technologies and how the use cases differ between internal combustion […]
