Just to report back for anyone in future going down this path:
>>>
http://www.siliconchip.com.au/Issue/2018/December/An+incredibly+sensitive+Magnetometer+to+buildThis is a slightly wacky design using mains transformers as pick-up coils and 4096UB hex inverters as amplifiers. Interesting though.
>>> Re: interesting parts
Here are the headline specs of some interesting parts (the first two suggested above) :
HMC1002 - 1 nT/sqrt(Hz) / +-2G full scale / 1 and 2-axis / magnetoresistive analogue
DRV425 - 1.5 nT/sqrt(Hz) / +-20G full scale / 1 axis / fluxgate analogue
RM3100 - 15 nT total rms noise / +-8G full scale / 1-2-3 axis / 'magneto-inductive' hall effect with packaged asic supporting I2C/SPI
MMC5883MA - 40 nT total rms noise / +-8G full scale / 3 axis / magnetoresistive supporting I2C
New (as yet unnamed) TDK part - 40nT total noise / ?G full scale / 3 axis / magnetoresistive with asic supporting ? protocols
https://www.tdk.com/corp/en/news_center/press/20180109_01.htm>>> They use instruments from Danish Instruments and Bartington. / Equipment range from a few thousands $ to a few tens thousands $. The exact FGE they use is about 30k $
Interesting snippet thanks, but atm I'm looking for components atm to build into some prototypes.
- Looks like I need to dig into the datasheets to unravel the noise numbers properly...
Alan
p.s. the HMC1002 seems the most honest / forthcoming re its noise characteristics.