Gaussmeter Hall Probe Sensor - Page 1
Forum section: electronics / projects

author: H713
author_rank: Regular Contributor
timestamp: January 09, 2025, 10:44:51 pm
content: Greetings,I'm looking to build some gaussmeters for operation up to about ~0.5T and I was wondering if anyone is aware of a commercially available hall sensor with an analog output and reasonable accuracy (say, 3% or better). I know I could buy probes from someone like Bell or Lakeshore, but at $500 per probe (minimum, more if it's a Lakeshore), I wanted to see what I could come up with first.

author: TimFox
author_rank: Super Contributor
timestamp: January 09, 2025, 10:59:22 pm
content: I can’t help you with a source other than FW Bell, but pay attention to the voltage sensing wire configuration, which separates the Hall voltage from resistive voltage difference due to the excitation current.

author: Poroit
author_rank: Frequent Contributor
timestamp: January 10, 2025, 06:12:20 am
content: G'day H713,Lutron make Gaussmeters and you may be able to buy a spare probe.https://www.lutroninstruments.eu/search/?string=gauss+meters

author: moffy
author_rank: Super Contributor
timestamp: January 10, 2025, 08:36:31 am
content: This Hall effect sensor might be suitable:https://www.allegromicro.com/-/media/files/datasheets/a1366-datasheet.pdf

author: Doctorandus_P
author_rank: Super Contributor
timestamp: January 10, 2025, 11:32:40 am
content: I had a look at the datasheet of the A1366 too, and it may work. The problem with HALL sensors, is that they tend to be too sensitive. The most insensitive version of this one (A1366LKT-1-T has a sensitivity of 1mV/Gauss, so that would be 5V for a half Tesla.( 10.000G = 1T)https://en.wikipedia.org/wiki/Tesla_(unit)I was bumping into the same problem when I had interest in a Gauss meter. Nearly all are too sensitive. There are plenty of commercial Gauss meters available, but they are quite expensive.

author: mtwieg
author_rank: Frequent Contributor
timestamp: January 10, 2025, 02:05:45 pm
content: Years ago I was working on a project for sensing strong (like +/-100mT fields) and yes at such high fields there are very few options to choose from. There are a couple parts on my old spreadsheet which might be worth looking at:MLX90295 and MLX90288 from Melexis. From what I can tell these are digitally configurable for different sensing ranges, though the process for configuring them doesn't look user-friendly. Might be able to get them factory-programmed.A company calledAsensoralso advertises some wide range hall sensors, though it's not even clear how they distribute.

author: PtrH
author_rank: Newbie
timestamp: June 16, 2025, 04:23:05 pm
content: Hi, just go toasensor.euand you can order them directly.I wrote a document showing an easy way to try out analog Hall sensors. Or to use them in precision test equipment. This will work for other current driven sensors too:https://asensor.eu/onewebmedia/An easy way to do Hall measurements.pdf

author: dmendesf
author_rank: Frequent Contributor
timestamp: June 18, 2025, 11:07:39 am
content: Another option is the ALS31313KLEATR-JOY. The ALS31313 famili is a triaxis (X,Y,Z) hall sensor with configurable +-500, 1000 or 2000G, but the -JOY has 1/4 sesibility in the Z axis so goes to 8000G (0.8 Tesla). It´s I2C programmable and readable.

author: dmendesf
author_rank: Frequent Contributor
timestamp: July 07, 2025, 01:38:33 am
content: Just found the DRV5053-Q1 that has an option with –11 mV/mT gain and can be powered by 38V. If my math (and understanding of the datasheet) is right it can measure ±3.5 Teslas.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 07, 2025, 03:39:20 pm
content: A while ago I had an idea of putting a cheap (70ct) Hall sensor inside an electromagnet, with the goal of varying the current through the electromagnet to null the Hall sensor output, and then measure the current. You'd have to calibrate it (big helmholtz coils?) and I have no idea what sort of resolution or accuracy you can get this way. I never built it, but the idea may be worth exploring.

author: TimFox
author_rank: Super Contributor
timestamp: July 07, 2025, 03:56:16 pm
content: A carefully-constructed and dimensioned Helmholtz coil pair can be calibrated from first principles for field vs. current.In Physics labs, we used such coils where the aluminum forms had openings cut to allow the student to measure the actual coil dimensions with a suitable calipers.

author: mtwieg
author_rank: Frequent Contributor
timestamp: July 07, 2025, 04:08:53 pm
content: Quote from: dmendesf on July 07, 2025, 01:38:33 amUnfortunately the part has limited Vout range (0.2V to 1.8V) which is independent of supply voltage. So the useful sensing range of these parts is +/-73mT at most.Quote from: Doctorandus_P on July 07, 2025, 03:39:20 pmSure, this can work to extend the operating range of the sensors. Basically like a closed loop hall effect current sensor. Though with very strong fields like 500mT you will have to contend with the substantial torques/forces between the coil and magnet, and the heat generated by the coil...

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 07, 2025, 04:09:51 pm
content: Quote from: TimFox on July 07, 2025, 03:56:16 pmYes, indeed. That is the idea. You put a small Helmholtz coil around your HALL sensor, as I assume you want to keep the sensor relatively small. And because of that it has relatively big deviations from the ideal values. So you use a bigger, more accurately constructed Helmholtz coil to calibrate the sensor setup. Helmholtz coils are reltaively common in lab setups and also commercially available.https://duckduckgo.com/?t=h_&q=helmholtz+coils&ia=images&iax=images