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  #71  
Old 10-23-2010, 02:10 PM
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Originally Posted by Wet_Boots View Post
Dial gauges of any sort wouldn't do to measure instantaneous forces. I know I can look at a dial swing at a valve closing, and make a good guess as to whether I need to worry or not, but I'd want more detail than that.
explain further please
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Old 10-23-2010, 02:12 PM
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Just curious, because I've seen my meters peg and never really knew what the bump was. My liquid-filled meters go to 125 psi and they pegged!
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Old 10-23-2010, 02:24 PM
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I've installed some 300 psi gauges when it looked like the 200 psi gauges were going to peg on a regular basis.
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Old 10-23-2010, 02:28 PM
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Russ has one of these, but I've not used it to measure spikes. www.dicksondata.com/matrix/pressure_products.php
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Old 10-23-2010, 02:50 PM
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Measuring pressure without gauges - http://en.wikipedia.org/wiki/Pressure_sensors
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  #76  
Old 10-23-2010, 03:00 PM
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i have 2 watts spike or maximum reading gauges, the only thing that i don't like is that they're dry and tend to bounce a little i don't think a liquid filled would as much.
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Old 10-23-2010, 03:24 PM
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Originally Posted by Wet_Boots View Post
I remember there being some fairly inexpensive pressure sensors available. Something akin to strain-gauge electronics, I believe. Flow would be tougher to get an instantaneous read on, I would think. I picture something like a pitot tube in a line, connected to another gauge.
Doppler flow meters www.greyline.com/products.htm

Quote:
Originally Posted by Wet_Boots View Post
Dial gauges of any sort wouldn't do to measure instantaneous forces. I know I can look at a dial swing at a valve closing, and make a good guess as to whether I need to worry or not, but I'd want more detail than that.
please explain

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Originally Posted by Wet_Boots View Post
I've installed some 300 psi gauges when it looked like the 200 psi gauges were going to peg on a regular basis.
what's this got to do with your statement "Dial gauges of any sort wouldn't do to measure instantaneous forces."

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Originally Posted by Wet_Boots View Post
Measuring pressure without gauges - http://en.wikipedia.org/wiki/Pressure_sensors
i love the badgers, answer the friggin question!

sorry, it's all that time i've been spending with kiril

Last edited by 1idejim; 10-23-2010 at 03:26 PM. Reason: that's the first time that multiple quotes have worked for me
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  #78  
Old 10-23-2010, 03:41 PM
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You can't measure instantaneous forces with measuring devices that have moving parts, since those moving parts will be subject to inertial forces. The reading would lag the actual event, if it was even accurate in the first place. It will probably take a piezoresistive, or piezoelectric, sensor to get the job done.
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  #79  
Old 10-23-2010, 04:00 PM
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Originally Posted by Wet_Boots View Post
You can't measure instantaneous forces with measuring devices that have moving parts, since those moving parts will be subject to inertial forces. The reading would lag the actual event, if it was even accurate in the first place. It will probably take a piezoresistive, or piezoelectric, sensor to get the job done.
makes sense, i installed some piezometers to log ground shift for a developer a number of years ago.

they're also used in well water and sewage studies.

but we can also look at the definition;

instantaneous [ˌɪnstənˈteɪnɪəs]
adj
1. occurring with almost no delay; immediate
2. happening or completed within a moment instantaneous death
3. (Mathematics) Maths
a. occurring at or associated with a particular instant
b. equal to the limit of the average value of a given variable as the time interval over which the variable is considered approaches zero instantaneous velocity
instantaneously adv
instantaneousness , instantaneity [ɪnˌstæntəˈniːɪtɪ] n
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Old 10-23-2010, 04:19 PM
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Just how instantaneous this could be, for sake of measuring, I don't know. Figure on sensors hooked up to a storage oscilloscope. I'm certain the needle swings I saw on a 300 psi gauge were indicating pressures above 150 psi, and yet the Richdel 1-1/2 inch master valve didn't blow up.
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