Sat Jun 16, 2012 12:00 am
i never intended the system to be accurate, i designed it around the parameters that it would have some proportionality (either linear, geometric, or some variation, it would be possible to figure this out by putting it in a tank with a guage known to function accuratly) that could be observed to compare the intensity of various pressure bursts in relation to the change in different variables. If the system were to be truly accurate, the friction and mass of the piston (a plunger from a syringe) would have to be accounted for both with acceleration and deccelleration, nearly verbatum to what you were describing, DYI. Yet the accuracy you describe may be futile, as long as the device measures the same every time, then it will fulfil its intentions of a comparitive device (the only condition i see that would require accurate pressure measurements would be in scaling it up to a full sized effecient cannon, yet the pressure data probably will not scale up to an accurate full sized cannon, though it may be interesting to see the varience in pressure busts depending on burn effeciency, geometry or size). Although, if anyone is going to attempt so many varying pressure experiments, it may be worth it to invest in an accurate digital manometer. I know that the vernier instrument that i have used in my science class can get to relatively small time intervals, and its a pretty cheap and easy system to set up. The speed and accuracy would of course be dependent on how much money someone will spend, but a digital system will instantly give a graph back of pressure v time, and could even be set up to simultaneously measure temeraure... but i'm sure most that have taken high school chemistry know all this...
DYI: i have observed that people will generally accept a constructive critic. I've been reading some of your posts, i'm not sure if you realize this (you seem to have had some implication toward calling yourself a downer), but a slightly subjective tone comes out of your writing that isolates people, and that may be the reason why some people tend to ignore you (but more generally, downers). Further reasoning may lie in the subject matter, you implied that people that provide insight as to why a theory may fail get ignored, they generally get ignored because people that are reviewing an idea are thinking of ways to make it work, instead of trying to troubleshoot something that hasn't been tried.