Test kits...No idea. we dont use em'
But for the elemental our lab uses a panalytical axios.
it does everything, not just those elements. We analyse all the additives in the oil and control our sulfur spec..
our unit is one of the larger more expensicve ones but i think from memory when we bought this one there were others in the cheaper range...and smaller...
I dont know how it all works, but its awesome we just type in a name for the sample, hit go and out comes the results everytime on spec..
i dont know where you come from so if you want to speak to em' the internet address is
www.panalytical.comcheers