Test/Measurements category

Revolutionizing Electric Field Measuring Techniques

Nowadays, electrical fields are being used not only in electrical engineering, but also for industrial, weather forecasting, safety, and medical applications. As a result, the need for a precise electric field strength measurement device has become increasingly high, and many investigations have devoted their resources to creating such device. TU Wien has developed a small electric field sensor that is much simpler, and most importantly, it is less prone to distortion.

There are a lot of measurement systems in the market. However, most of them are big, depend on complex surrounding calibration procedures, or the device is grounded to provide a reference measurement. All these factors cause distortion that affects the measurement. Additionally, dielectric devices develop surfaces charges that also lead to distortion, and conductive metallic components can have the same effect.

The sensor made by TU Wien is made from silicon forming a small, grid shaped structure fixed onto a small spring, so that when the silicon is exposed to an electrical field a force is exerted on the silicon crystals causing the spring to compress or extend. Another grid was added to make these slight changes visible. The silicon grid is lined up, so when movement occurs, light can pass through which is then measured and used to calculate the electrical field. It can only measure strength not direction, and it can be used for fields of up to 1 k Hz.  The silicon structures are just a few micrometers in diameter making it much smaller than conventional sensors.

This method of measurement is new, Andreas Kainzs from the Institute of Sensor and Actuator Systems says that in the future they would be able to achieve even better results as the measuring technique matures. The sensor is a micromechanical systems (MEMs) that has the potential for replacing the measuring techniques used nowadays. This device is not only less prone to distortion, but also portable, easy to transport and capable of fitting into wearables. The prototype has can measure weak fields of less than 200 volts per meter. This means that in terms of measuring capabilities, this sensor can easily compete with those already in the market. The sensor is not currently being sold, and TU Wien plans on keep improving the device.


Arduino Milliohm Meter

danielrp @ instructables.com writes:

This is an accurate milliohm meter with a maximum resolution of 0.1mOhm. The design is very simple, the whole assembly can be built in a couple of hours once all the parts are gathered. It is based on a precision current sink and a high-resolution ADC controlled by an Arduino Nano V3. It uses a Kelvin connection with the resistor under test to exclude the resistance of test leads from the measurements. It can be very useful for measuring small resistors and the resistance of PCB traces, motor coils, inductance coils, transformer coils, or calculate the length of wires.

Arduino Milliohm Meter – [Link]

Pokit – Multimeter, Oscilloscope & Logger in your pocket

Pokit – Multimeter, Oscilloscope & Logger in your pocket – [Link]

Physicists design $100 handheld muon detector

by Jennifer Chu | MIT News Office:

Now physicists working in MIT’s Laboratory for Nuclear Science have designed a pocket-sized cosmic ray muon detector to track these ghostly particles. The detector can be made with common electrical parts, and when turned on, it lights up and counts each time a muon passes through. The relatively simple device costs just $100 to build, making it the most affordable muon detector available today.

Physicists design $100 handheld muon detector – [Link]

Continuity Tester using ATtiny85

This article describes a simple continuity tester based on an ATtiny85. The tester features a buzzer that sounds to help you determinate the trace continuity. It is designed for checking circuit wiring, or tracing out the tracks on a PCB. According to it’s author David Johnson-Davies it has a low threshold resistance of 50Ω to avoid false positives, and passes less than 0.1mA through the circuit under test, to avoid affecting sensitive components. It’s powered from a small button cell, and automatically switches itself off when not in use, avoiding the need for an on/off switch.

HeartyPatch – Open source ECG patch with Wifi

An ECG patch with HRV monitoring that’s open source, affordable, and Wi-Fi/Bluetooth connected.

HeartyPatch is a completely open source, single-lead, ECG-HR wearable patch with HRV (Heart Rate Variability) analysis. It is based on the popular ESP32 system-on-a-chip. By using low-cost, highly-integrated components, we are able to keep the BOM’s cost low, while the simplicity of the circuit design means future expansion will be easier. HeartyPatch can be used both as a lifestyle device for managing fitness and stress as well as for diagnostics and medical research, with the potential for even more interesting applications.

HeartyPatch – Open source ECG patch with Wifi – [Link]

Four-Channel Thermometer on OLED display

David Johnson-Davies @ technoblogy.com build a four-channel thermometer that monitors the temperature at four temperature sensors, and gives a continuous readout on a small 128×32 OLED display. It’s a useful project for various applications like PSU or PC monitoring. The article describes 1-wire and code in details.

It could be used in any application where you want to monitor multiple temperatures, such as in controlling a greenhouse, checking the output transistors in a power amplifier, monitoring key points in an overclocked gaming PC, monitoring the chips on a Raspberry Pi, or checking the temperature in different rooms in a home.

Four-Channel Thermometer on OLED display – [Link]

Rigol general-purpose 200MHz scopes from under €600

RIGOL Technologies introduces its new DS2000E Series Oscilloscope, a 200MHz, 2 channel scope that continues RIGOL‘s tradition of combining unmatched capabilities at unprecedented price points to transform the test and measurement industry.

The DS2000E is available at either 100MHz or 200MHz bandwidths.  All models provide 2 analog channels with 50 Ω input impedance standard.  With real-time sample rate of 1GS/Sec (on both channels), memory depth of up to 28Mpts standard, and waveform capture rate up to 50,000 wfms/sec, the DS2000E provides the raw instrument performance required to meet today’s more advanced debug challenges.  When coupled with the large 8 inch WVGA intensity graded display, complete network connectivity, hardware waveform record/playback, serial trigger and decode, and other advanced analysis capabilities, starting at just $647, engineers and technicians will see RIGOL has again transformed the price performance assumptions in the Basic Oscilloscope Market.

Rigol general-purpose 200MHz scopes from under €600 – [Link]

Open Radiation Detector

Quickly identify radioactive materials with a pocket-sized ion chamber. Built from standard parts for easy manufacture and low cost. by Carlos Garcia Saura:

Radioactivity is invisible and can be harmful to life. The goal of this project is to provide a simple device that could prevent cases of radiation poisoning. Professional radiation meters can be very accurate, but are also expensive, complex and fragile (most use vacuum discharge tubes made of glass). However in many occasions we only want to determine whether an object is radioactive or not.

Open Radiation Detector – [Link]

MappyDot – Micro Smart LiDAR Sensor

Blecky @ hackaday.io:

MappyDot is a smart ranging sensor which provides system designers with the ability to measure accurate distances on drones and robotic platforms for collision avoidance, area mapping, distance measurement, gesture recognition and motion sensing. The MappyDot uses the VL53L0X laser time-of-flight ranging sensor from STMicroelectronics, which is a tried and tested 940nm Class 1 laser sensor in use in millions of devices worldwide.

MappyDot – Micro Smart LiDAR Sensor – [Link]