I'm using an SSR 25AVA. My primary testing worked out OK, so I need to build a bit bigger bench and sort out a plate so I can get figures for every 5 CFM. I guess I could set it at every 10CFM and then use some sort of equation to set the curve between points at 1 or even 1/2 CFM intervals.
Can anyone shed some light on how I can do that?
Floating Depression?
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1960FL
- Posts: 1339
- Joined: Fri Jan 08, 2010 10:36 pm
- Location: Maryland
Re: Floating Depression?
Baker,
If you are going to try and put some value in this data you need to adopt some standards for your testing, first is a Standard voltage say 100VAC at the motors, just as in the other benches we use the 10" or 28" or 40" depression standard. Then you will need you adopt a consistent means to make your orifice calibration plates I/E 1/8" AL plate cut with a Home Depot hole saw say 3/4" holes up to 2" by 1/4" increments to capture your data, these should be burr free. Then you will use Ed's spread sheet to check calibration and determine just what CD the plates are acting on.
Example, i put the 3/4" plate on top and set the voltage to 100VAC at the motor the depression reads 100" i use Ed's sheet based on this ID and DeltaP, i would start with a CD of about .58 so you would be at 71 CFM then on to the next plate test again enter all this data into an excel sheet and plat the graph. You could then perform extrapolations between points following the natural curve of the graph.
I am just trying to talk through what you are trying to do at the low budget thought level.
Rick
If you are going to try and put some value in this data you need to adopt some standards for your testing, first is a Standard voltage say 100VAC at the motors, just as in the other benches we use the 10" or 28" or 40" depression standard. Then you will need you adopt a consistent means to make your orifice calibration plates I/E 1/8" AL plate cut with a Home Depot hole saw say 3/4" holes up to 2" by 1/4" increments to capture your data, these should be burr free. Then you will use Ed's spread sheet to check calibration and determine just what CD the plates are acting on.
Example, i put the 3/4" plate on top and set the voltage to 100VAC at the motor the depression reads 100" i use Ed's sheet based on this ID and DeltaP, i would start with a CD of about .58 so you would be at 71 CFM then on to the next plate test again enter all this data into an excel sheet and plat the graph. You could then perform extrapolations between points following the natural curve of the graph.
I am just trying to talk through what you are trying to do at the low budget thought level.
Rick
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Bakerlite
- Posts: 80
- Joined: Sat Feb 25, 2012 8:34 am
Re: Floating Depression?
Yeah, I was thinking of using Excel to graph it. I can make the orifices no problems.
So far it's been a fun project
So far it's been a fun project
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Tony
- Posts: 1445
- Joined: Wed Mar 03, 2010 3:40 pm
- Location: Melbourne, Australia
Re: Floating Depression?
The biggest problem will be the motors themselves.
Setting to an exact voltage is not going to guarantee anything like a constant rpm or pressure because the electrical resistance of the motor windings will change due to temperature and airflow through the motor.
A motor tachometer might help a lot with consistency if there is only one motor, but how to apply that with multiple motors I have no idea.
Setting to an exact voltage is not going to guarantee anything like a constant rpm or pressure because the electrical resistance of the motor windings will change due to temperature and airflow through the motor.
A motor tachometer might help a lot with consistency if there is only one motor, but how to apply that with multiple motors I have no idea.
Also known as the infamous "Warpspeed" on some other Forums.
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1960FL
- Posts: 1339
- Joined: Fri Jan 08, 2010 10:36 pm
- Location: Maryland
Re: Floating Depression?
Been a while Tony, but what i think i was trying to do was point the Floating depression folks into looking at some sort of comparative standard, not just O'h it flows more. What has what impact on flow I/E in a fixed depression bench we have that as one of our standards.
Rick
Rick