Frequently asked questions on electromagnetic measurement in the applications

The purpose of these Frequently Asked Questions (FAQs) is to answer most of questions in order to help you to understand better the measuring performances and advantages of using Kapteos technologies inside the applications.

Most of your frequently asked questions in the medium and high voltage applications

FAQs of measurement of electric fields in medium or high voltage

In power transmission, it is to diagnose a fault occurred in operating such an insulation fault, a blackout of the grid.
All the components involved in the electrical network infrastructure may be subject to a defect or be a need for aging analysis such as an insulator which would produce partial discharges.
From a normative point of view, it is required to measure human exposure to electric fields (Specific Absorption Rate or SAR).
Finally analyses of the purity of the 50 or 60 Hz fundamental frequency system are necessary through high harmonic measurements of electrical fields.

For analysis or monitoring the line infrastructure, expensive security systems are used by logging physically on the line to be monitored through resistive or capacitive bridges.
For the measurement of human exposure, there are measuring devices with metal antenna from the ground which give an effective value of the electric field. These devices can monitor and analyse for example the influence of lightning strikes.
To address all issues of fault analysis, infrastructure monitoring, aging equipment, exposure of people or analysis of network quality, Kapteos offers its eoSense system coupled to one or more probes.

First of all, a single system addresses all measurement problems for an electric field in medium and high voltage.
The measuring probe is very compact (5mm x 35 mm), very accurate in time and space. It allows the measurement of a field vector (amplitude, phase, spectrum, vector direction) rather than a simple effective (rms) measure.
The measurement is completely insulated and secure (even for lines up to several hundred kilovolts) through the insulated probe and its fibre optic (up to 100 meters) for the transport of information measured without being disturbed by strong electromagnetic fields.
Finally the probe perfectly functioning between 0 and 50 °C, allows a field measurement by not being sensitive to temperature.

The Kapteos solution enables high detailed analysis of the raised issues.
The customer can therefore understand very quickly the situation and at a much reduced cost, to take actions for improvement or correction.
The customer can rely on a Kapteos expert to be helped anywhere in the world.

Here are some typical examples:

  • 25kV cable ageing analysis (SNCF)
  • Electric field mapping of a 25kV insulator with partial discharges analysis (SNCF)
  • Electric field mapping of a bus bar inside an electrical network infra-structure (GE)
  • Analysis of partial and total discharges of a medium voltage system (EDF, UQAC (University of Québec at Chicoutimi) for the Hydro-Québec customer)

Most of your frequently asked questions in Magnetic Resonance Imaging (MRI) application

FAQs of measurement of electric fields in magnetic resonance imaging

The topic is to measure the exposure of people to electromagnetic fields.
The radio frequencies field analysis is required with a very high spatial resolution.
The measure must be performed under a magnetic field of 3 or 4.7 Tesla depending on the MRI model.

Theoretical simulations and empirical implementation rules are mainly considered.
There are certainly ways to measure but remain inaccessible outside MRI manufacturers.
Kapteos offers its eoSense system coupled to one or more probes perfectly suited to this application.

The proposed Kapteos solution is perfectly suited for this need because the probe:

  • Is non-invasive (it does not include metal, so do not alter the electric field to be measured) which is ABSOLUTELY requested in this market
  • Is very small, it allows an extreme localised measurement
  • Allows measurement of ultra-wideband electric field
  • Enables vector measurement of the electric field with excellent rejection ratio of an axis of the field to another. The measured information is very comprehensive and accurate.
  • Remains insensitive to the variation of temperature within a range of 0 to 50 °C
  • The signal to be measured can be remoted up to a distance of 100 metres

To measure very precisely the Specific Absorption Rate (SAR) of people inside the system (in the air on inside a phantom). Current research focused on in-vivo SAR assessment.
To improve the design knowledge of MRIs.

Peer reviewed articles have been published by Kapteos on this subject.
Measurement tests of electric fields under 3 and 4.7 Tesla were carried out with very good results.
A partnership is underway with the biomedical imaging research laboratory in Lyon (Créatis).
Sale of a measurement system, after validation by comprehensive tests at the Tübingen Clinic (Germany).

Most of your frequently asked questions in Specific Absorption Rate (SAR) assessment application

FAQs of measurement of electric fields for exposition of people (SAR)

The target is to perform measurements in accordance with standards requiring in-situ electric field in a biological medium.
Emitting electrical fields sources, are becoming more numerous, have a very broad frequency range (from kHz to GHz) and a range of signal amplitude.
The main emission sources are typically:

  • WI-FI
  • Bluetooth
  • Cell phones
  • Induction wireless charging systems (small electronic equipment, cars, buses …)
  • Induction furnaces
  • Energy transport
  • Antennas (TV, radio, telephone, defence …)

Companies employing personnel must ensure that this one does not work in conditions related to dangerous electromagnetic fields for the human body.

The SAR measurement is done following two completely different principles:

  • By a temperature measurement
  • By an electric field measurement

For electric field measurements, there are mainly two ways:

  • The measurement based on antennas
  • The measurement based on electro-optics (the solution proposed by Kapteos).

The proposed Kapteos solution is perfectly suited for this need because the probe:

  • Is non-invasive (it does not include metal, so do not alter the electric field to be measured) which is ABSOLUTELY requested in this market
  • Is very small, it allows an extreme localised measurement
  • Allows measurement of ultra-wideband electric field
  • Enables vector measurement of the electric field with excellent rejection ratio of an axis of the field to another. The measured information is very comprehensive and accurate.
  • Remains insensitive to the variation of temperature within a range of 0 to 50 °C

One system that perfectly meets the standards in force (for frequencies from 100kHz to 40GHz).
It allows the measurement of a field vector (amplitude, phase, spectrum, vector direction).

Several publications have been made with the XLIM research institute (www.xlim.fr), specialized in bioelectromagnetics and a world reference.
Sale of a measurement system, after validation by comprehensive tests at the Tübingen Clinic (Germany).
Sale of a measurement system with numerous sensors for measuring infantrymen exposure to electric fields from military communications antennas (DGA).

Kapteos is national research coordinator of projects dedicated to in-situ analysis of the Specific Absorption Rate (SAR).
Kapteos is expert for the National Health Safety Food Agency, Environment and Labour (ANSES) in France (www.anses.fr)

Most of your frequently asked questions in plasma application

FAQs of measurement of electric fields inside plasma

Firstly it concerns the measurements of very strong electric field (kV/m to MV/m) in order to ionize a gas containing charged particles.

The measure of this field must be physically very close (few millimetres or less for cold plasma to tens of centimetres for hot plasmas) and very localized. Finally the shape of the electric field of a plasma is extremely complex.

In general, there are cold plasmas for biomedical and hot plasmas for industry (metal processing or semiconductor for example).

The power supply voltage measurement of the plasma generator determines a number of information but it is very limited.
Theoretical simulations are possible but do not allow to take into account the reality of the implemented technical solutions.
Kapteos offers its eoSense system coupled to one or more probes perfectly suited to this application.

The Kapteos solution is a unique solution and widely validated by extensive testing.

The proposed Kapteos solution is perfectly suited for this need because the probe:

  • Is non-invasive (it does not include metal, so do not alter the electric field to be measured)
  • Is very small, it allows an extreme localised measurement
  • Allows measurement of ultra-wideband electric field
  • Enables vector measurement of the electric field with excellent rejection ratio of an axis of the field to another. The measured information is very comprehensive and accurate.
  • Remains insensitive to the variation of temperature within a range of 0 to 50 °C

A full monitoring of the plasma generation means to improve the quality of plasma and its performances.

In-situ plasma vectorial electric field mappings by several customers with different environments such as biological or magnetic (GREMI University in Orleans (France) or the INP Greifswald University (Germany)).

Most of your frequently asked questions in antennas application

FAQs of measurement of electric fields emitted by antennas

To measure near electric fields (inside the antenna, over the aperture or in the near field region).
The measured E-field must contain the amplitude and phase of each component (or axis) of the field vector.
The measured E-field has a very wide frequency band (from few kHz to several GHz).

Mainly to date, there are mini-dipole and mono-pole antennas which all contain a metal part. This metal part alters the electric field to be measured.
Kapteos offers its eoSense system coupled to one or more probes perfectly suited to this application.

The proposed Kapteos solution is perfectly suited for this need because the probe:

  • Is the same solution for all bandwidth
  • Is non-invasive (it does not include metal, so do not alter the electric field to be measured)
  • Is very small, it allows an extreme localised measurement
  • Allows measurement of ultra-wideband electric field
  • Enables vector measurement of the electric field with excellent rejection ratio of an axis of the field to another. The measured information is very comprehensive and accurate.
  • Remains insensitive to the variation of temperature within a range of 0 to 50 °C
  • The signal to be measured can be remoted up to a distance of 100 metres

To validate the full operation of the antenna with a simple, fast and costless solution.
To acquire new information for the future development of new generations of antennas.

Vectorial electric field mappings of horn and patch antennas (or other investigated shapes) were performed at several customers facilities (CEA, CSTB).
Vectorial electric field mappings were performed internally at Kapteos.
Several technical papers have been published by Kapteos.

Most of your frequently asked questions in ElectroMagnetic Compatibility (EMC) application

FAQs of measurement of electric fields related to electro-magnetic compatibility

Kapteos is mainly targeting companies facing issues with EMC:

  • At R&D stage
  • At commissioning
  • During operation

The typical applications which may be involves are:

  • Drives (variable speed devices)
  • UPS (Uninterruptable Power Supplies)
  • Solar invertors
  • Windmills invertors
  • Power supplies
  • PCBS with several tens of volts (on short distances)
  • Railways
  • Mining

For the time being, Kapteos is not targeting the market of E-field measurements linked to IEC standards within an anechoic chamber.

To measure low (up to very high) E-fields in near field from few tens of Hz to several tens of MHz under several 100s of volts.

Mainly to date, there are mini-dipole and mono-pole antennas which all contain a metal part. This metal part alters the electric field to be measured.
Kapteos offers its eoSense system coupled to one or more probes perfectly suited to this application.

The proposed Kapteos solution is perfectly suited for this need because the probe:

  • Is the same system for all aboved mentioned applications
  • Is non-invasive (it does not include metal, so do not alter the electric field to be measured)
  • Is completely insulated and secure (even for lines up to several hundred kilovolts)
  • Is very small, it allows an extreme localised measurement
  • Allows measurement of ultra-wideband electric field
  • Enables vector measurement of the electric field with excellent rejection ratio of an axis of the field to another. The measured information is very comprehensive and accurate.
  • Remains insensitive to the variation of temperature within a range of 0 to 50 °C
  • The signal to be measured can be remoted up to a distance of 100 metres
  • A mapping of the E-field may be performed with a scanner

Fast and very accurate measurements.
Safe measurement (insulated probe).
Comprehensive data to perform rapidly improvements, actions, corrections or mitigations.

Bus bar E-field mapping (GE – CH)
PCB E-field mapping (NXP Semiconductors – FR)