Diver one of sixteen to die using high-tech gear

[DRE]

I can\"t speak to the Cislunar I never considered it as it was way out of my means(about $25,000)
Checking the sensors(there are three) at depth is easy. Being a good Tec. diver you always know what fraction of 02 you are breathing and you know how deep you are. It's a simple matter to take f02xata and calculate the PP02. When you know that you just do a Diluent flush and check to see if your 02 sensors are reading correctly. John J. that just posted to the list puts duct tape on the back of his handset and enters all the numbers on the surface(no math a depth)

I'm sorry if I'm misunderstanding this, but if you have a machime that gives you your bottom gas by mixing O2 and a diluent on the fly, your fraction of O2 is determined by this mixing process. So aren't you basing your fO2 on the a priori assumption that that is what the machine is going to give you anyway. So in case the O2 sensors are all off the mark, the machine will mix you a gas which the machine assumes gives you the correct ppO2 at depth and that's the readout you'll get on your display (based upon the data from those same O2 sensors). Now you have to assume that's something might be wrong, do the diluent flush and then find out that your sensors are off the mark, all while you're 260ft inside the Kamloops. Then you have to deploy your bailout bottle (unless you have left the bottles outside of the wreck to maintain a smaller profile) because you can no longer be sure of what your machine is mixing for you - that is, if you haven't toxed out yet at that point and make it to the surface and do your entire deco on your bailout bottles. At the same time your team member has a catastrophic gas failure on his Inspiration, his deco bottle starts freeflowing and then what?
Granted, this might be somewhat of an unusual scenario, but weirder things have happened...

Also, could you please elaborate on how you calculate your gas requirements for any given dive?