Passive sensor gathers target data through the detection of physical
phenomena. A passive sensor is a which just ‘listens’ to what is happening,
contrary to active sensors that need to transmit a signal into the environment
and measure the response.
Passive sensor detects electromagnetic radiation emitted or reflected from a
source. Sensor converts an external stimulus to an output signal.
Microwire is a wire of small diameter (on a micro-scale). RVmagnetics
produces glass coated bistable MicroWires using Ulitovsky-Taylor method.
Calibration constant is the coefficient used to convert the value acquired by
MicroWire sensor into physical quantity. For calibrating MicroWire sensors
RVmagnetics uses standard calibration constant.
For electronic setup there is no general sketch, schematic or block
diagram – it is always customized based on the existing design, limitations,
noise levels, environment etc.
Power consumption depends on the measurement frequency and also depends on
the electric and magnetic properties of the environment.
Pressure, temperature, position in the magnetic field, but also also electric
current, torsion, stress, vibration … Read more about the measurement.
One MicroWire is sufficient to perform a measurement of e.g. temperature,
mechanical strain, etc. More MicroWires are employed when use case requires
creating the „heat map“ of a physical quantity. Sensing head is able to read
multiple MicroWires in its vicinity,
Estimated cost of the sensor unit depends on the volume of R&D /
customization work and also on order volume of sensors. In higher volumes (over
1 million units a MicroWire unit can be provided at a price below 1 EUR).
Sensing head and electronics part varies significantly.
We are measuring the time occurrence of the magnetization reversal process in
the MicroWire. This is a unique magnetic response from the MicroWire to the
external magnetic field. We separate the response from the measured external
magnetic field(s) and from our excitation AC magnetic field. Read more about principles of measuring for MicroWire.
The accuracy and sensitivity of our custom developed sensor can be adjusted
with chemical composition of the MicroWire, diameter of MicroWire, design of the
electronics and other parameters. Read more about the difference between accuracy and
Now, the maximum range is up to 10cm in ideal conditions (low electric and
magnetic fields). In presence of strong electric and magnetic fields, or
„pushing“ the signal through several mm thick metallic / magnetic walls
sensing distance shortens.
Our sensor generates a unique signal. In the case of strong interference, the
response from the wire can be obtained simply by averaging of the received
The longer the wire, the better the signal. Typically 1 cm sensor is ideal
for sensing, but for some applications we use up to 4 cm long wire. In ideal
conditions the shortest MicroWire of 6mm length can be used. Find out more about
MicroWire in the basic technical overview