Temperature is a widely measured real-world physical variable, but achieving credible results is harder than it seems, even for a simple device such as a kitchen oven. Calibration of a sensor and its associated electronics channel before making critical measurements or monitoring system performance is a common requirement in many situations. In some cases, it’s […]
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Graphene-based flowmeter sensor measures nano-rate fluid flows, Part 3: The sensor
The first part of this article looked at the challenges of sensing nano-level flow rates such as found in the blood vessels. In contrast, the second part looked at graphene, an allotrope of elemental carbon at the heart of a new sensor used to measure those flows. This third and final part looks at the […]
Graphene-based flowmeter sensor measures nano-rate fluid flows, Part 2: The graphene context
The previous part of this article looked at the challenges of nanoflow sensors, especially with respect to blood flow. This part looks at graphene, which is the basis for the new sensor. Graphene is a material structure which did not exist until relatively recently. However, its constituent element of graphite – the crystalline form of […]
Graphene-based flowmeter sensor measures nano-rate fluid flows, Part 1: The challenge
When it comes to nearly all biological measurements, the ranges of many of the parameters of interest are orders-of-magnitude below those with which many engineers are familiar. Instead of megahertz or even kilohertz, the living-creature world is in the single or double-digit hertz range, such as the roughly 60+ beats per minute (BPM) for a […]
What are the different types of fingerprint scanners?
Fingerprint scanners, which were once reserved for biometric logging systems and attendance systems, are now part of regular smartphones and much more. Fingerprints have been a trusted method of personal identity. Combined with face id or other biometric identification systems like retina scanning, fingerprints offer an impeccable way to recognize any person. With a blast […]
Using optical fibers for temperature measurement, Part 3: Variations
Among the many ways to sense temperature, combinations of advanced optical principles used with optical fibers offer very different approaches, with application advantages and implementation limitations. The previous part of this article looked at two approaches to using optical fibers for temperature sensing based on the fiber Bragg grating (FBG) and the Mach-Zehnder interferometer (MZI). […]
Using optical fibers for temperature measurement, Part 2: Principles
Among the many ways to sense temperature, combinations of advanced optical principles used with optical fibers offer very different approaches, with application advantages but also implementation limitations. The first part of this article discussed general issues of sensing of physical parameters, especially temperature, and total internal reflection in optical fibers. This section will look at […]
Using optical fibers for temperature measurement, Part 1: Context
Among the many ways to sense temperature, combinations of advanced optical principles used with optical fibers offer very different approaches, with application advantages and implementation limitations. Temperature is the most widely sensed physical parameter; it’s that simple. What’s not simple is the many ways we have of measuring it through the use of sensors such […]
Analyzing different proximity sensor technologies
Utilized as a no-touch method to provide either precise distance measurement to an object or simple “there/not there” logic, proximity sensors span a wide range of technologies, each offering their own set of operating principles, advantages, and drawbacks. Some of the most commonly found technologies in portable or small embedded systems include ultrasonic, photoelectric, laser […]
Undersea optical-fiber cables do double-duty as seismic sensors, Part 2: Application
A research team has devised and tested a scheme based on advanced optical-physics principles, which uses active submarine optical-fiber data cables also to sense ocean-floor earthquakes and ocean-surface swells. The previous part of this article established the context for “piggybacking” seismic-sensing capabilities onto an existing undersea fiber-optic cable. This part looks in more detail at […]
