Leslie Judson Jones
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6]http://www.youtube.com/watch?v=38pcX_0FQzU6]
THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM METER
- Thread starter Leslie Judson Jones
- Start date
Bob Foster
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Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
Remember this one? It verifies the video above.
Another TNT on propane with a #4 Little Giant. The only thing is this Judson TM is 26 years old with the original blower.
e]http://www.youtube.com/watch?v=uyNLW57lXBwe]
Remember this one? It verifies the video above.
Another TNT on propane with a #4 Little Giant. The only thing is this Judson TM is 26 years old with the original blower.
e]http://www.youtube.com/watch?v=uyNLW57lXBwe]
NobleCarpetCleaners
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- Noble Carpet Cleaners
Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
Must be nice having all that money that allows you to dink around that much in your shop. Instead of truck mounts, I would invest it in rental property.
Must be nice having all that money that allows you to dink around that much in your shop. Instead of truck mounts, I would invest it in rental property.
Burtz
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Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
"Must be nice having all that money that allows you to dink around that much in your shop. Instead of truck mounts, I would invest it in rental property"
so is that supposed to mean
"Must be nice having all that money that allows you to dink around that much in your shop. Instead of truck mounts, I would invest it in rental property"
so is that supposed to mean
Bjorn
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Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
z]http://www.youtube.com/watch?v=0Up4DbA9L_8z]
z]http://www.youtube.com/watch?v=vZGWmH2hlT8z]
z]http://www.youtube.com/watch?v=0Up4DbA9L_8z]
z]http://www.youtube.com/watch?v=vZGWmH2hlT8z]
Todd Anthony
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Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
AWESOME Machine Les. I Love that big stainless recovery tank. Will last forever.
AWESOME Machine Les. I Love that big stainless recovery tank. Will last forever.
Bill Soukoreff
Member
Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
Les, so there is no filter in the tank? You just use an inline filter?
I second giving credit to Joe. Not only for cool cuffs but also the high sheer kits and numerous other tweaks like his custom soft touch valve kits, low profile wand thermometers, Vinus wand and other goodies.
Les, so there is no filter in the tank? You just use an inline filter?
I second giving credit to Joe. Not only for cool cuffs but also the high sheer kits and numerous other tweaks like his custom soft touch valve kits, low profile wand thermometers, Vinus wand and other goodies.
Mike Draper
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Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
with 325' out I'm at 252 cfm and 10" lift. Thats all 2.4" hose and 25' of 2".
with 325' out I'm at 252 cfm and 10" lift. Thats all 2.4" hose and 25' of 2".
gary mackay
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Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
I'm tryin some Joe stuff, can't remember what the hell it is but we'll see, wait, booties were on the list to replace those booties that go "Snap" when you try tro put them on. Friggen Commy Chinks & then Obama borrowing billiions from them every day like any other Ghetto Fook stick trying to make that BMW payment & rent on a $200 a week welfare check! They can afford to cut back in the quality department, hell, they own you your children & thier children.
I'm tryin some Joe stuff, can't remember what the hell it is but we'll see, wait, booties were on the list to replace those booties that go "Snap" when you try tro put them on. Friggen Commy Chinks & then Obama borrowing billiions from them every day like any other Ghetto Fook stick trying to make that BMW payment & rent on a $200 a week welfare check! They can afford to cut back in the quality department, hell, they own you your children & thier children.
Bob Foster
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Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
Tell us what you really think....
gary mackay said:
Tell us what you really think....
Zee
Supportive Member
Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
Did I hear correctly? Walt Bush's new truckmount?! So Walt you are done with your current truckmount or is it because the manufacturer shut down you going a different rout?
I am intrigued by the Judson truckmounts- I can't wait to hear how this will serve you!
Did I hear correctly? Walt Bush's new truckmount?! So Walt you are done with your current truckmount or is it because the manufacturer shut down you going a different rout?
I am intrigued by the Judson truckmounts- I can't wait to hear how this will serve you!
Larry Cobb
Member
Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
Good Video, Les.
I have used that same Extech CFM meter for testing at Nick's Bar B Q here in Texas.
It has to be programmed to convert air speed to CFM.
Since it is not reading all of the airflow, I am concerned about the accuracy in all the videos.
John at Mytee has been using a new CFM meter that appears to be more accurate,
since it reads the entire airflow stream.
Hi Power portable with booster 1 min. video:
http://www.youtube.com/watch?v=HVIBnuq50h4&feature=related
Accurate Testing is good for this industry.
Larry
Good Video, Les.
I have used that same Extech CFM meter for testing at Nick's Bar B Q here in Texas.
It has to be programmed to convert air speed to CFM.
Since it is not reading all of the airflow, I am concerned about the accuracy in all the videos.
John at Mytee has been using a new CFM meter that appears to be more accurate,
since it reads the entire airflow stream.
Hi Power portable with booster 1 min. video:
http://www.youtube.com/watch?v=HVIBnuq50h4&feature=related
Accurate Testing is good for this industry.
Larry
Mike Draper
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Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
if you use the same meter for all the trucks I would think that would give you accurate performance of all the trucks.
if you use the same meter for all the trucks I would think that would give you accurate performance of all the trucks.
Dolly Llama
Number 5
Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
it would indeed
but may or may not be the actual CFM
don't know how one would go about calibrating it either .
maybe using an uncorked (on both ends) blower and using manufacture CFM specs thru the RPM curve to see if it reads same values ???
..L.T.A.
Mike Draper said:
it would indeed
but may or may not be the actual CFM
don't know how one would go about calibrating it either .
maybe using an uncorked (on both ends) blower and using manufacture CFM specs thru the RPM curve to see if it reads same values ???
..L.T.A.
Bob Foster
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Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
From what I see the Extech meter is reliable and it is the meter everyone is testing with. Show me why or how this other spring loaded thing is supposed to be more reliable and accurate than an electronic device that is self-calibrating?
From what I see the Extech meter is reliable and it is the meter everyone is testing with. Show me why or how this other spring loaded thing is supposed to be more reliable and accurate than an electronic device that is self-calibrating?
dgardner
Moderator
Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
Great video, Les! While the Extech meters are fairly accuarate, there is indeed one issue with the way they are being used. It is a well known fact that velocity is not consistent at every point across the duct or hose cross-section. The air flows noticably slower the nearer you get to the walls (due to friction losses), and faster towards the center. The air balance contractors that deal with building HVAC systems know this, and when they measure CFM they do what's called a traverse. This means they take several velocity measurements at different (well defined) points, from as few as four on up, depending on the size of the duct, and average them together.
So when you hand-hold the instrument and take a single reading, the measurement is just not repeatable, and probably not accurate. You would have to fasten it down so it can't move between readings just to get a repeatable (but not necessarily accurate) reading. And everyone generally moves the turbine around 'till they get the highest reading, but, as I mentioned, this is slightly higher than the true CFM because not all of the air is moving that fast. Another problem is the airflow transitions between two different diameters (the hose and the funnel) just inches before the measurement is taken. As the air flows through the transition it speeds up (which is the whole reason for using the funnel, the velocity in the hose is too fast for the Extech). Taking the measurement so close to the transition means there is all sorts of turbulence that skews the reading. All flowmeter manufacturers specify a certain number of duct diameters of straight run to get a good reading. Typical numbers are 10 diameters upstream and 4 downstream. For a 4 inch funnel this means you would need a pipe 56" long. What we're doing is not perfect by a long shot, but it's a start.
The 'spring loaded thingy' (piston flowmeter) does not have this problem because all of the air flows through it, which makes it self-averaging. This makes it more repeatable (and possibly more accurate, depending on other factors).
If Les would be willing to show readings with the turbine centered vs. offset (edge of the turbine against the edge of the funnel), the difference would be apparent.
Great video, Les! While the Extech meters are fairly accuarate, there is indeed one issue with the way they are being used. It is a well known fact that velocity is not consistent at every point across the duct or hose cross-section. The air flows noticably slower the nearer you get to the walls (due to friction losses), and faster towards the center. The air balance contractors that deal with building HVAC systems know this, and when they measure CFM they do what's called a traverse. This means they take several velocity measurements at different (well defined) points, from as few as four on up, depending on the size of the duct, and average them together.
So when you hand-hold the instrument and take a single reading, the measurement is just not repeatable, and probably not accurate. You would have to fasten it down so it can't move between readings just to get a repeatable (but not necessarily accurate) reading. And everyone generally moves the turbine around 'till they get the highest reading, but, as I mentioned, this is slightly higher than the true CFM because not all of the air is moving that fast. Another problem is the airflow transitions between two different diameters (the hose and the funnel) just inches before the measurement is taken. As the air flows through the transition it speeds up (which is the whole reason for using the funnel, the velocity in the hose is too fast for the Extech). Taking the measurement so close to the transition means there is all sorts of turbulence that skews the reading. All flowmeter manufacturers specify a certain number of duct diameters of straight run to get a good reading. Typical numbers are 10 diameters upstream and 4 downstream. For a 4 inch funnel this means you would need a pipe 56" long. What we're doing is not perfect by a long shot, but it's a start.
The 'spring loaded thingy' (piston flowmeter) does not have this problem because all of the air flows through it, which makes it self-averaging. This makes it more repeatable (and possibly more accurate, depending on other factors).
If Les would be willing to show readings with the turbine centered vs. offset (edge of the turbine against the edge of the funnel), the difference would be apparent.
dgardner
Moderator
Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
Bob, for one thing the Extech is certainly not 'self-calibrating'. And it does not even measure CFM, it measures velocity. What it does have is a built-in calculation where you enter the duct (hose) area in square feet (or inches) and it figures CFM for you, i.e. velocity (in FPM) X area (in sq. feet) = CFM. I can make Les's reading anything I want by telling the instrument different area constants. One problem is placing the turbine housing over the funnel changes the true area that the airflow sees, so if you just measure the funnel I.D. your calculated CFM will instantly be in error. The method being used here could not be expected to give an accuracy better than around +- 10% or so, or worse.
But Les's demo was less about a totally accurate reading than it was about repeatability, in other words, what was important was the difference between the two setups. If he just fastens down the turbine so it can't move between changes we would see a fairly accurate difference. So the absolute values may not be perfect but the difference CFM would be very close.
Bob Foster said:
Bob, for one thing the Extech is certainly not 'self-calibrating'. And it does not even measure CFM, it measures velocity. What it does have is a built-in calculation where you enter the duct (hose) area in square feet (or inches) and it figures CFM for you, i.e. velocity (in FPM) X area (in sq. feet) = CFM. I can make Les's reading anything I want by telling the instrument different area constants. One problem is placing the turbine housing over the funnel changes the true area that the airflow sees, so if you just measure the funnel I.D. your calculated CFM will instantly be in error. The method being used here could not be expected to give an accuracy better than around +- 10% or so, or worse.
But Les's demo was less about a totally accurate reading than it was about repeatability, in other words, what was important was the difference between the two setups. If he just fastens down the turbine so it can't move between changes we would see a fairly accurate difference. So the absolute values may not be perfect but the difference CFM would be very close.
dgardner
Moderator
Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
Close. The blower mfgr's don't specify CFM for open flow, but do specify it at a few vacuum points. For instance, if you look at Root's vacuum performance curves for a 45, they are at 6" hg, 10", 14" and 16".
If you rigidly mount the flow pickup 2/3 of the way down a straight pipe around 4' long, put a ball valve between the pipe and the blower, tap in an accurate vac gauge between the blower and the valve, run the blower at a precise rpm (measured at the blower pulley with an accurate tach), close down the valve until you hit one of the chart values, say, 10", then you could calibrate the Extech to the CFM on the blower chart and come very, very close, if the blower is new (or nearly new). If you then move the pipe/extech as an assembly, you would have an accurate, repeatable measurement system. You would still have to normalize the reading according to elevation/barometric pressure, and temperature. Roots' chart only applies if the ambient temp is 68F and the atmospheric pressure is 30" hg. Accurately measuring airflow is not trivial for sure!
meAt said:
Close. The blower mfgr's don't specify CFM for open flow, but do specify it at a few vacuum points. For instance, if you look at Root's vacuum performance curves for a 45, they are at 6" hg, 10", 14" and 16".
If you rigidly mount the flow pickup 2/3 of the way down a straight pipe around 4' long, put a ball valve between the pipe and the blower, tap in an accurate vac gauge between the blower and the valve, run the blower at a precise rpm (measured at the blower pulley with an accurate tach), close down the valve until you hit one of the chart values, say, 10", then you could calibrate the Extech to the CFM on the blower chart and come very, very close, if the blower is new (or nearly new). If you then move the pipe/extech as an assembly, you would have an accurate, repeatable measurement system. You would still have to normalize the reading according to elevation/barometric pressure, and temperature. Roots' chart only applies if the ambient temp is 68F and the atmospheric pressure is 30" hg. Accurately measuring airflow is not trivial for sure!
Bob Foster
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Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
Interesting points. http://www.dwyer-inst.com/Products/AirV ... uction.cfm
You might have noticed in my video that my machine had very similar readings as Les had with his. When I did the test you could see some fluctuations in the readings as I moved the head to hunt out not necessarily the highest but the most consistent reading.
The testing instrument that Mytee used looks like it could be purchased fairly inexpensively. Can you tell us what the make and model of that instrument was so that I can get my hands on one.
I see differences in testing method and equipment being used as an excuse for units not meeting their claimed performance. So let's start the process off by having everyone who submits a video test the EXACT same way.
It would be a good education (and entertaining for some) to watch this process unfold. Also this information is very relevant to the our cleaning performance.
You want to bet that this testing and comparing between manufacturers might just become political because of what's at stake? !gotcha!
Interesting points. http://www.dwyer-inst.com/Products/AirV ... uction.cfm
You might have noticed in my video that my machine had very similar readings as Les had with his. When I did the test you could see some fluctuations in the readings as I moved the head to hunt out not necessarily the highest but the most consistent reading.
The testing instrument that Mytee used looks like it could be purchased fairly inexpensively. Can you tell us what the make and model of that instrument was so that I can get my hands on one.
I see differences in testing method and equipment being used as an excuse for units not meeting their claimed performance. So let's start the process off by having everyone who submits a video test the EXACT same way.
It would be a good education (and entertaining for some) to watch this process unfold. Also this information is very relevant to the our cleaning performance.
You want to bet that this testing and comparing between manufacturers might just become political because of what's at stake? !gotcha!
dgardner
Moderator
Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
I believe this is the one mentioned:
http://www.omega.com/ppt/pptsc.asp?ref=FL500&Nav=greb04
I believe this is the one mentioned:
http://www.omega.com/ppt/pptsc.asp?ref=FL500&Nav=greb04
Bob Foster
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dgardner
Moderator
Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
Are you sure? If you look closely at the Mytee video, I believe the brand is Omega, and it didn't look like a variable area meter like the one you linked to.
Are you sure? If you look closely at the Mytee video, I believe the brand is Omega, and it didn't look like a variable area meter like the one you linked to.
Bob Foster
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Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
I thing your right. Just have to get the one that has the correct inlet outlet size. I'm assuming that you can go to a 3" and bush it down to 2" without it compromising. The Mytee looks like it could be a 2".
The price is good too.
I thing your right. Just have to get the one that has the correct inlet outlet size. I'm assuming that you can go to a 3" and bush it down to 2" without it compromising. The Mytee looks like it could be a 2".
The price is good too.
Leslie Judson Jones
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Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
Thanks for the link I will get one.
LES
dgardner said:
Thanks for the link I will get one.
LES
Bob Foster
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Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
Mytee Video
Omega website
Mytee Video
Omega website
dgardner
Moderator
Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
This is a very good article for those interested in the intricacies involved in airflow measurement, with a very good description of traverse measurments. I've been using Dwyer instruments for 30 years, and they've been in the airflow biz for several decades more than I've been alive.
Bob Foster said:
This is a very good article for those interested in the intricacies involved in airflow measurement, with a very good description of traverse measurments. I've been using Dwyer instruments for 30 years, and they've been in the airflow biz for several decades more than I've been alive.
Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
how many geeks need to prove the carpet is dry?
I usually check with my hand to see how well the vacuum in my machines do,
step 1 wipe your hand against the carpet
step 2 if it seems to wet go back and do more dry strokes
how many geeks need to prove the carpet is dry?
I usually check with my hand to see how well the vacuum in my machines do,
step 1 wipe your hand against the carpet
step 2 if it seems to wet go back and do more dry strokes
dgardner
Moderator
Re: THE TRUTH WILL SET YOU FREE !!! with JOE BRISTOR'S CFM M
About two more geeks than are required to change a light bulb.
XTREME1 said:
About two more geeks than are required to change a light bulb.
