Hey guys,
I'm sure some of you have gauss meters in your tool collections.
Just curious on what you use?
I'm going to get one for measuring neo magnets and some coils etc....
Post what you use and pros and cons
Thanks guys heaps!!
I'm sure some of you have gauss meters in your tool collections.
Just curious on what you use?
I'm going to get one for measuring neo magnets and some coils etc....
Post what you use and pros and cons
Thanks guys heaps!!
I don't know if any gauss meter exist as a meter itself. Perhaps you can build one using Hall Effect sensor and a display (analog or digital). It may be OK to masure spayed magnetic field around a coil, but you can't measure it into a closed iron circuit, introducing it will create an air gap that drastically affect magnetic flux.
Gauss? That's an old "standard". We use Tesla nowadays.
Anyway Gauss sensors are still available, even modern sensors: https://www.pasco.com/products/sensors/wireless/ps-3221#specs-panel
Gauss-meters do exist, and they are used in a variety of applications: deflection systems for camera's and CRT's (now somewhat discontinued), nuclear physics, electrodynamic transducers like speakers, MHD flow-meters, etc.
Maybe the name has evolved (Tesla-meter?), but the instrument still exist and has real applications. I built one for myself two or three decades ago
Maybe the name has evolved (Tesla-meter?), but the instrument still exist and has real applications. I built one for myself two or three decades ago
Tesla is too big. 1 Tesla is 10,000 Gauss. It's like using mile markers to meaure inches.
Maybe so, but the meter both exists and is normally called Gauss-meter, go figure.
So much so that:
https://www.gaussmeter.co.uk/?gclid...FBKVysYuwmc8qlSxU-M-K6qcZKyvPuWMaAs6jEALw_wcB
https://www.metravi.com/what-is-a-gauss-meter-or-magnetometer/
https://play.google.com/store/apps/details?id=com.keuwl.gaussmeter&hl=en&gl=US&pli=1
https://www.keuwl.com/GaussMeter/
https://www.pce-instruments.com/eng...-meters/gauss-meter-tesla-meter-kat_40056.htm
and that´s just from the first search page.
They are readily available. F. W. Bell (fwbell.com) is a well known and popular manufacturer. They produce a wide range of instruments and probes. Also, you can search for magnetometers.
There are/were several hall sensor semiconductors on the market that can be useful for simple applications.
FWIW Gauss is a cgs unit of measure and Tesla is an SI unit of measure. Both are used often depending on the industry custom.
There are/were several hall sensor semiconductors on the market that can be useful for simple applications.
FWIW Gauss is a cgs unit of measure and Tesla is an SI unit of measure. Both are used often depending on the industry custom.
Last edited:
Gauss... I know Tesla nowadays, yeh I just call them gauss meters haha.
I just need to know how strong magnets are and electro magnets too. The ones I looked at are like heaps!! I was hoping around $400au which is $270us which is 256 euro which is 220 pounds just so you know lol. or at that price are they just junk and not accurate?
Cheers
I just need to know how strong magnets are and electro magnets too. The ones I looked at are like heaps!! I was hoping around $400au which is $270us which is 256 euro which is 220 pounds just so you know lol. or at that price are they just junk and not accurate?
Cheers
Bell no longer makes Gauss meters, just probes. Start off with a cheap meter, since lab meters are rather costly.
An application: many years ago I used one to compare/measure magnetization in some speakers prototypes introducing the sensor in their gaps while the cone/coil was not glued yet. I can't recall details, but it was a Gauss meter and pretty expensive.
I make loudspeakers, big problem is that most regular Gaussmeters can´t measure "that high" and for us a 1T to 2T range is needed, but to boot gaps are both narrow (probe should be 1 mm thick) and curved which constricts space even more.
Imagine a 1 mm wide, 14mm diameter tweeter gap, it´s very hard to find a probe that fits.
Long ago I used a magnetoresistive probe whose tip was like a match body (not head) which could fit in, used it together with a matching Italian multimeter, result was non linear but they supplied a calibration curve.
Problem is that I lent it to an IDIOT who tried to measure WHILE MAGNETIZING a speaker and DESTROYED it.
In any case, always when I have a measurement problem I go back to "basic principles" as shown in a Physics Book.
I make a custom "exploration" voice coil, just a couple turns, and sweep the gap, the output feeding a ballistic galvanometer equivalent; in this case an integrating Op Amp with a long time constant (over 10 seconds) and keep that value readable and stable by using a sample and hold circuit.
Result gives me total flux in Maxwells, then I divide it by gap surface to get Gauss .
Sorry, retired old school Engineer here, so still use old style units.
Not forgetting that for everyday "technical" use they are more practical 😉
Now where did I put my slide ruler ? 😉
PS: always mumbling about and maybe some day I actually do it: I should make my own paper thin Hall probe 😱
Yes, what you just read.
Modern ones are bought ready made and are built around some kind of semiconductor surfaces to give them high sensitivity, able to measure Earth magnetic field and such, but the basic Hall principle does not imply semiconductors at all, just one metallic conductor strip (copper?) passing current, submerged in a perpendicular magnetic field, and measuring voltage difference between strip edges .... very doable with a piece of flexible PCB material I think.
Should be calibrated, of course.
Imagine a 1 mm wide, 14mm diameter tweeter gap, it´s very hard to find a probe that fits.
Long ago I used a magnetoresistive probe whose tip was like a match body (not head) which could fit in, used it together with a matching Italian multimeter, result was non linear but they supplied a calibration curve.
Problem is that I lent it to an IDIOT who tried to measure WHILE MAGNETIZING a speaker and DESTROYED it.
In any case, always when I have a measurement problem I go back to "basic principles" as shown in a Physics Book.
I make a custom "exploration" voice coil, just a couple turns, and sweep the gap, the output feeding a ballistic galvanometer equivalent; in this case an integrating Op Amp with a long time constant (over 10 seconds) and keep that value readable and stable by using a sample and hold circuit.
Result gives me total flux in Maxwells, then I divide it by gap surface to get Gauss .
Sorry, retired old school Engineer here, so still use old style units.
Not forgetting that for everyday "technical" use they are more practical 😉
Now where did I put my slide ruler ? 😉
PS: always mumbling about and maybe some day I actually do it: I should make my own paper thin Hall probe 😱
Yes, what you just read.
Modern ones are bought ready made and are built around some kind of semiconductor surfaces to give them high sensitivity, able to measure Earth magnetic field and such, but the basic Hall principle does not imply semiconductors at all, just one metallic conductor strip (copper?) passing current, submerged in a perpendicular magnetic field, and measuring voltage difference between strip edges .... very doable with a piece of flexible PCB material I think.
Should be calibrated, of course.
The Hall effect also exists in conductors (not only semi's), but it is really tiny.
To put figures on it, I would need to revisit the Hall constants/coefficients, but I am pretty sure that for copper, an induction of 1 or 2T would be barely detectable using a zero-drift amplifier.
A graphite layer sprayed on an insulating carrier sheet would probably work better, but there again I have no idea about the coefficients.
For the Hall effect to be significant, you need a high drift speed of charge carriers in an electric field, and in good conductors like copper, this speed is extremely low for reasonable current densities
To put figures on it, I would need to revisit the Hall constants/coefficients, but I am pretty sure that for copper, an induction of 1 or 2T would be barely detectable using a zero-drift amplifier.
A graphite layer sprayed on an insulating carrier sheet would probably work better, but there again I have no idea about the coefficients.
For the Hall effect to be significant, you need a high drift speed of charge carriers in an electric field, and in good conductors like copper, this speed is extremely low for reasonable current densities
I used to use a fluxgate magnetometer, but that is for week magnetic fields. It is based on magnetic core saturation, where the core is driven with a saturating AC input and the ambient field modifies the pulse width in 3 axes. You can build your own with a small ferrite core.
There are a bunch of gaussmeters you can choose from the GMW site
Plus a comprehensive guide on magnetometers you can read.
Hope that helps!
Plus a comprehensive guide on magnetometers you can read.
Hope that helps!
No Tesla is the guy (or the car), the unit is the tesla, symbol T, S.I. makes a clear distinction between the people and the units named after them.
Agree. Earth's magnetic field averages about 0.6 or so Gauss. Does Maxwell have a magnetic strength named after him, too?
I had a Bell Gauss meter it was fine. However this may be the best for speaker magnetics:
Sensitive Research Fluxmeter Not common but they work with the voice coil you will be using. Similar to what Mr Fahey proposed. However its important to know what to do with your measurements.