REFLECTOR: Running LOP

[Bernard Despins]

The THX system can be implemented using instrumented spark plugs (like 
the PRISM system) instead of drilling and tapping a new hole.  You send 
the plug you want to instrument (automotive style in my case)  to a 
company which uses electrical discharge machining to bore a hole in the 
right place and then install the pressure probe. 

I've looked into the ionic sensing concept, but could not find enough 
information.  The biggest problem that I could find, was that the signal 
being monitored is very small compared to the large voltage spikes 
occurring in neighboring plugs.  All commercial pressure monitors I 
could find used a system of fiber optics to measure the movement of a 
tiny diaphragm .  This decoupled the noise.  I'm sure ionic sensing is 
coming though...

Bernard

Brian Michalk wrote:
> I'm all over pressure sensing.  I looked at your link.  It looks like 
> you need to drill and tap a new hole.
>
> Have you thought about ionic pressure sensing?  I'm going to build one 
> for myself one of these days after I'm flying.
>
> GAMI says they can run avgas with diesel contamination and with PP 
> sensing, the engine runs without detonation.
>
> This would solve the lead problem, but I think Volvo or SAAB has a 
> patent on the ionic sensing thing.
>
>