Test/Measurements category

Fast Single-Pixel Camera

Compressed sensing is an new computational technique to extract large amounts of information from a signal. Researchers from Rice University, for example, have built a camera that can generate 2D-images using only a single light sensor (‘pixel’) instead of the millions of pixels in the sensor of a conventional camera.

This compressed sensing technology is rather inefficient for forming images: such a single-pixel camera needs to take thousands of pictures to produce a single, reasonably sharp image. Researchers from the MIT Media Lab however, have developed a new technique that makes image acquisition using compressed sensing fifty times more efficient. In the example of the single-pixel camera that means that the number of exposures can be reduces to several tens.

One intriguing aspect of compressed sensing is that no lens is required – again in contrast with a conventional camera. That makes this technique also particularly interesting for applications at wavelengths outside of the visible spectrum.

In compressed sensing, use is made of the time differences between the reflected light waves from the object to be imaged. In addition, the light that strikes the sensor has a pattern – as if it passed through a checkerboard with irregular positioned transparent and opaque fields. This could be obtained with a filter or using a micro-mirror array where some mirrors are directed towards the sensor and others are not.

The sensor each time measures only the cumulative intensity of the incoming light. But when this measurement is repeated often enough, each time with a different pattern, then the software can derive the intensity of the light that is reflected from different points of the subject.

Source: Elektor

110 GHz spectrum analyzer fits in your pocket

The MS2760A is the latest release in the Ultra-portable family of USB driven instruments – it can perform spectrum measurements from 9kHz to 110GHz in the industries smallest and lightest form factor. by Clemens Valens @ elektormagazine.com:

There was a time, and not so long ago, that spectrum analyzers were large and heavy instruments that had to be wheeled around on a trolley or mounted in a van for field operations. And their upper frequency stopped at say 10 GHz for the really expensive ones. Oh, how things have changed! Today it is possible to carry a spectrum analyzer in your pocket, or stick it on a drone and fly it around. What’s more, it measures frequencies up to 110 GHz.

110 GHz spectrum analyzer fits in your pocket – [Link]

How to Build a Bi-Fuel (LPG & Unleaded) Trip Computer Using Arduino

Nikos Stavrou @ instructables.com build a bi-fuel trip computer using arduino and has a detailed tutorial on it. The computer can measure both LPG and unleaded fuel consumption. He writes:

The main reason I made this project is the lack of a trip computer that is designed for LPG powered cars.

I named it Bi-TripCo as it can measure the fuel consumption for both fuel systems of a Bi-Fuel car (LPG and Unleaded).

Some might say: “ok, a similar one, no big deal!”. Don’t rush.There are many (or some) tools out there, that can calculate the consumption of conventional fuel systems, which are very easy to use: just plug it into the OBD port of your car – unless you have an older car which does not have one, like mine. And, of course, there are some very good implementations based on Arduino, which can calculate many things related to the Unleaded fuel consumption. But those tools can not be used on an LPG powered car.

How to Build a Bi-Fuel (LPG & Unleaded) Trip Computer Using Arduino – [Link]


USB Curve Tracer

A small and inexpensive USB-based curve tracer used for troubleshooting electronics in the style of the Huntron Tracker 2000. by Jason Jones:

This documents a USB-based curve tracer based on the PIC24FV16KM202, which is a modest 16-bit microcontroller. The board uses a PC screen OR an oscilloscope in XY mode as a display and may connect to multimeter probes for functionality.

USB Curve Tracer – [Link]

How to Make an Arduino Capacitance Meter

circuitbasics.com has a tutorial on how to measure capacitance using arduino.

With all the different ways capacitors are labeled, figuring out the values of your capacitors can be challenging. Especially if you don’t have a digital multi-meter to test them. In this tutorial, I’ll show you how to build three different capacitance meters using an Arduino and a couple resistors. After finishing this project, you’ll be able to measure all of your capacitors and label them for future reference.

How to Make an Arduino Capacitance Meter – [Link]

Using HealthyPi with a PC for ECG,Respiration & SpO2

Ashwin K Whitchurch, Venkatesh Bhat, and Manikandan S @ hackster.io build a PC based ECG,Respiration & SpO2 monitor.

We introduced the HealthyPi as a HAT add-on for the Raspberry Pi, turning it into a full-featured, medical-grade open patient monitor. However, we realized later that people also wanted to use the board standalone with a Windows/Linux/Mac PC. We already had an on-board USB port from the SAMD21 on the board.

Using HealthyPi with a PC for ECG,Respiration & SpO2 – [Link]

Keysight adds 50/70/100 MHz oscilloscopes for educators, small labs

Martin Rowe @ edn.com writes:

Taking aim at rivals Rigol and Tektronix, Keysight Technologies has introduced a series of four oscilloscopes aimed at educators, small labs, and perhaps individuals. The InfiniiVision 1000 X-Series of two-channel oscilloscopes has bandwidths of 50 MHz, 70 MHz, and 100 MHz (upgradeable from 70 MHz with a software key) with prices starting at $449 (see table).

Keysight adds 50/70/100 MHz oscilloscopes for educators, small labs – [Link]

Keysight MXA signal analyzer / Spectrum analyzer review, analysis & experiments

Keysight MXA revision-b signal analyzer / Spectrum analyzer review, analysis & experiments from The Signal Path:

In this episode Shahriar reviews the long awaited Keysight MXA Signal Analyzer (N9020B). The new X-Series Spectrum Analyzers from Keysight offer an entirely re-designed GUI interface which supports multiple tabs as well as multi-touch interaction.

Keysight MXA signal analyzer / Spectrum analyzer review, analysis & experiments – [Link]

Measuring seismic activity using ProtoCentral OpenPressure

Seismic activity or “Vibrations of the earth” is measured using ProtoCentral’s OpenPressure 24-bit DAQ System.

A geophone is a magnetic device used to measure the Earth’s normal vibrations (some abnormal during events such as earthquakes). These movements are also present when there is a small explosion (commonly used for mining and exploration purposes).

Measuring seismic activity using ProtoCentral OpenPressure – [Link]