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 […]
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 […]
Undersea optical-fiber cables do double-duty as seismic sensors, Part 1: Context
A research team has devised and tested a scheme based on advanced optical-physics principles which uses active submarine optical-fiber data cables to also sense ocean-floor earthquakes and ocean-surface swells. Sensing of physical parameters such as temperature, pressure, force, and velocity often brings a “split personality” analysis. On one hand, getting a reading of the basic […]
ICs for interfacing inductive sensors, Part 2
Designers who use inductive proximity sensors have a choice of high-performance signal-conditioning interface ICs, each offering different sets of features, functions, and capabilities. The first part of this article discussed some of the sensing opportunities and looked at an IC from Texas Instruments. This part looks at ICs from Renesas and Microchip Technology. Renesas IPS2550 […]
ICs for interfacing inductive sensors, Part 1
Designers who use inductive proximity sensors have a choice of high-performance signal-conditioning interface ICs, each offering different sets of features, functions, and capabilities. In two predecessor features (see References), we looked at the inductive proximity sensor and its basic operation (see References) but did not look at the electronic interface circuit for this widely used […]
What are inductive proximity sensors, Part 2
The first part of this article introduced the inductive proximity sensor. This second and final part looks at some more specifics of this sensor. Q: Are there different architectures and implementations? A: Yes, there are three basic types: 1) the magnetic elements alone are in the sensor. This separates the electronics from the sensing coils […]
