Em 2/7/2010 16:44, YES NOPE9 escreveu: >> On Jul 1, 2010, at 6:05 PM, Bob Blick wrote: >> >> I'm looking for a brake fluid pressure transducer to put in my car for >> data logging. >> >> The ones made for that purpose seem to be in the $150 range. >> >> Pressure transducers are not something I am looking at on a daily = >> basis >> so I don't know what the going rate for off-the-shelf industrial = >> models >> are, or where to buy them in single quantities. >> >> Basically brake fluid is fairly benign and the pressure is 0 to 1500 = >> PSI >> and accuracy is not that important. And I don't care what the >> input/output is, raw bridge, ratiometric, digital, whatever. >> >> Anyone been down this road before and can point me in the right >> direction? >> >> Thanks, >> >> Bob >> > > Is there a company that makes a fluid isolator/pressure multiplier ? = > Maybe something mechanical that has a 10:1 ( as an example ) surface = > ratio change so that 2000 psi on one side is 200 psi on the other ? > Gus A good machinist with a lathe and a grinder can make such device. A plunger inside a cylinder with an internal step (the plunger stepped also), the cross section of the bigger diameter portion with an area ten times that of the smaller diameter portion. High pressure applied to the smaller diameter end pushes the plunger, the pressure at the larger diameter end is 1/10 of the pressure at the smaller diameter end. The tricky part is the leakage, perhaps some O-Rings near each end with a hole through the cylinder wall, between the sections to drain any fluid that may leak from either side. The pressure reduction may be even higher, perhaps hundreds of times, to suit any pressure sensor you may find. A better option would be a device like this one but instead of using pressure at the larger diameter end, just attach a strain-gauge and read the pressure by means of the strain. Isaac __________________________________________________ Fale com seus amigos de gra=E7a com o novo Yahoo! Messenger = http://br.messenger.yahoo.com/ = -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist