Isaac Marino Bavaresco wrote:
>  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
>
> __________________________________________________
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>
>   =

This is a good idea I have worked on a device such as this on a machine =

I worked on.
The drain hole in the m middle is very important.

ALSO the seals used need special attention.  I cannot remember details =

but some types of seal material will come apart when exposed to brake fluid.

OLD BOB


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