# Measuring magnetic waves from coil

#### joshvik

Feb 21, 2023
3
Hi all,

Looking to measure some magnetic waves being generated at an electric coil. Freq is between 0-20kHz and magnitude is pretty small <1T. Any have suggestions for the best tool to measure and log data of this magnetic waveform?

Googling around, I found meters like this: https://www.alphalabinc.com/product/mr3/
I thought maybe even a simple hall sensor but not sure.

What do you suggest?

Thanks!

#### Delta Prime

Jul 29, 2020
1,807
It's not that simple. you may not know exactly what strength means in terms of magnetic properties.
Units used in magnet strength measurements.
Tesla : density of an magnetic field, flux density. T = kg / (A * s2)
A = amperes and s = seconds.
My favorite:
T = V * s / m2 or T = (N * s)/(C * m) or T = Wb / m2.
where V = volts, s = seconds, m = meters, N = newtons, C = coulombs and Wb = webers.
You want to measure a magnetic field in a coil. How about after you turn the power off and there's no magnetic field.
Gauss: is used to measure the remnants of the magnetic field (magnetic flux density).
One gauss is equal to 10-4 teslas. It can also be defined as 1 maxwell per square centimeter or 10-4 webers per square meter.
Then there is Oersted & Kilogram.
The latter being the force required to pull a magnet away from the flat metal surface that it is making full surface-to-surface contact.
Oersteds, is the force required to reduce a magnet's magnetic characteristics to zero.
A magnetometer, or gaussmeter, is used for measuring a magnetic field.
Wasn't that simple?
Hall effect Magnetometers that use the Hall effect use current to ascertain whether a magnetic field is nearby and how strong it is.
Magnetoinduction effects: Magnetometers that rely on magnet induction calculate how magnetized a certain material becomes when exposed to a magnetic field.
Magnetoresistance effects: Magnetometers that use magnetoresistance calculate an object's ability to change its electrical resistance when it becomes exposed to a magnetic field.

Last edited:

Feb 21, 2023
3

#### Delta Prime

Jul 29, 2020
1,807
The picture is in anticipation for your next question.

#### joshvik

Feb 21, 2023
3
I guess to come back to the original question: how do you suggest I measure these induced magnetic fields?

Should I buy a gauss meter or use a Hall effect sensor? Are there other options?

This is all new to me, so appreciate any help.

#### Delta Prime

Jul 29, 2020
1,807
If you want to measure the intensity and direction of the magnetic field use a magnetometer.
Sorry I should just said that in the first place,
By the way a magnetometer is also referred to as an EMF field strength meter, so when you get bored playing around with magnetic fields you can go catch ghosts

Last edited:

#### Martaine2005

May 12, 2015
4,902
I knew you would have to mention ghosts and EMF…. Boo!

S
Replies
81
Views
5K
K
M
Replies
14
Views
1K
Rich Grise
R
E
Replies
24
Views
2K
Dan Major
D
Replies
3
Views
465
Replies
14
Views
2K