hmm, may be he should thinking about using optical fiber bundles to  
remote  sensing instead... (fiber grating i believe already used to  
check for strain/stress, temperature (overheating))..
jk
On Sep 27, 2018, at 1:04 PM, David Hillman wrote:

> Hi Jack - I had the opportunity of talking about drill head  
> electronics
> when I was in Australia teaching an instruction course on QFN  
> technologies
> and assembly. A  product designer was literally looking to have his  
> entire
> assembly in a QFN package (which was why he was attending the  
> course). His
> electronics were located in the drill head itself and he was  
> measuring the
> ore body for various element content (gold, silver, tin, etc.) as  
> the drill
> was boring thru the ore body (think of a XRF or SEM running in the  
> drill
> head in real time). And you'll get a kick out of this - his biggest  
> issue
> was that physics was getting in his way as his electronics were  
> getting so
> small, the physics rules of the analysis technologies (i.e.  
> electron path,
> sample densities, focal length) wouldn't work. It was a very  
> educational
> and informative discussion for me.
>
> Dave Hillman
> Rockwell Collins
> [log in to unmask]
>
> On Thu, Sep 27, 2018 at 9:41 AM Jack Olson <[log in to unmask]> wrote:
>
>> just curious - what is the function of the circuit board at the  
>> end of the
>> drill?
>> I mean, what is it DOING at the bottom of the hole?
>>
>> On Thu, 20 Sep 2018 15:38:24 +0000, Stadem, Richard D <
>> [log in to unmask]> wrote:
>>
>>> I work for a company in Norway (in my spare time, LOL) who  
>>> manufactures
>> downhole electronics. It is a completely different world, building
>> electronics that must survive, MUST survive, in the world's harshest
>> environment, quickly going from typical 16-20 deg. C then to  
>> freezing while
>> in arctic water in the north Atlantic, then quickly ramping up to  
>> as hot as
>> 175 C during normal all-day drilling, sometimes hotter for a short- 
>> term
>> controlled drill, then it is flooded with a mix of oil and mud and  
>> gravel
>> and salt water, and the shock and vibration are beyond belief. You  
>> come
>> away with a different perspective on high-rel electronics than you  
>> ever had
>> before, believe me.
>>>
>>