DIY Pressure Transducer
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- Charles Acosta
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SailorBob wrote: here's the final fix. I was able to clean up the signal on the 200 psi transducer enough that it's useful for work:
Can you do a cranking or running waveform?
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www.scannerdanner.com/forum/post-your-re...i-at-idle.html#20351
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- Andy.MacFadyen
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Sooknanan wrote: (null)
I know the diy pressure transducers will with the pico 6 software.
But what I am asking is if the pico diagnostics software would recognize a diy p/t while conducting a compression test and populate for each cylinder.
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But pressure sensors aren't used for relative compression tests they are done be either an amp clamp on the starter cable or by the battery voltage method. The Pico software should have no problem with working on battery cranking voltage to give a measure of starter current.
From the Pico Automotive Website
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- Andy.MacFadyen
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One thing to be aware of with cranking voltage compression testing is old style starters tend to have much higher current draw than more modern starters which can be both geared and be the permanent magnet type.
Other thing to watch for is the number of cylinders --- 3 cylinder 4 strokes always have odd looking cranking voltage traces, 4 cylinder engines have noticeable high peaks and lower valleys than 6 or 8 cylinders and of course on diesels the much higher compression pressures puts huge loads on the starter.
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- bruce.oliver
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- bruce.oliver
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- bruce.oliver
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SailorBob wrote: Set the pico to use 1 khz low pass filtering and that should clean it up. You're just seeing electrical noise probably.
It's not noise. I am used to seeing that on waveforms. It's like Andy described, distinct steps in the waveform. Like the transducer responds to slow for the software.
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I am making a dedicated set of transducers myself that will be able to be used with either a pico or a verus..
15psi for Vacuum (which converts to 30 in Hg, which is what a regular vacuum gauge reads anyway),
150psi for fuel pressure (a fuel pressure gauge goes up to 140psi),
300psi for Gas engine compression (which is what a regualar gauge goes to),
and a 1000psi for Diesel engine compression (which is what a diesel compression gauge goes to.. Im a truck driver, I had to make one for trucks.. LOL)
over the Thanksgiving holiday, I am going to build the ones I have the stuff for so far.. for the electrical, I am using battery power/ground, then going to a 12v/5v stepdown to supply the transducers with the correct voltage.. there will be an LED at the power plug to let you know there is power, and an LED at the signal out to let you know there is signal going to the scope..
I will then post some videos showing them, and showing how to use them so you get the best results.. I dont have access to a verus but I will be testing it on a Hantek 1008C.. I have a 98 Infiniti I30 that will be my test mule..
but that wont be for another month and a half.. I just wanted to point out that the transducers use a 5v and produce a 0psi reading at 0.5v and maximum psi reading at 4.5.. have a good day..
heres a sneek peek at the labels..
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