Electric gold tester

Hi. Hope you all well.
Can anyone recommend me any electric gold tester to be able to analyse 9k-24k and Platinum?
Are they really working or will it be better to use testing acid?

Thanks
Gina

I know Quicktest have some - and they tend to be brutally honest about the capabilities of their machines.
I use acid (and iodine).

I can see one call KEE... maybe that is the best option?

I am too scared of acid. there was too much warning on the package. so I returned them to the store.. ��