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Clc420
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Laminar flow flame test
#26579392 - 04/05/20 12:21 PM (3 years, 9 months ago) |
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I just finished building my flow hood and done a flame test. It bends but there is a flicker to the flame. Is the flame supposed to be absolutely dead straight or do you get a bit of a flicker ?
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Pinball24
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Registered: 05/17/17
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Re: Laminar flow flame test [Re: Clc420]
#26582355 - 04/06/20 06:10 PM (3 years, 9 months ago) |
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Quote:
Clc420 said: I just finished building my flow hood and done a flame test. It bends but there is a flicker to the flame. Is the flame supposed to be absolutely dead straight or do you get a bit of a flicker ?
I've wondered the same and never could find the answer, but mine flickers a little bit and I haven't had any problems yet. Good luck and hopefully someone more experienced than us can answer this question.
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PiptheGreAtest
Aspiring Heavyweight


Registered: 07/18/16
Posts: 464
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Re: Laminar flow flame test [Re: Pinball24]
#26583008 - 04/06/20 11:39 PM (3 years, 9 months ago) |
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Ditto. Buying one premade like to know.
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Hobbit GDF
Deadhead



Registered: 02/14/19
Posts: 3,385
Loc: Terrapin station
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Mine goes smooth to flickering from 6inch away. No problems with mine either.
Try an incense stick. It will show you the flow alot more
Edited by Hobbit GDF (04/07/20 12:01 AM)
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TedsDead



Registered: 01/03/17
Posts: 4,998
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Re: Laminar flow flame test [Re: Hobbit GDF]
#26583150 - 04/07/20 02:22 AM (3 years, 9 months ago) |
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Ill bet its fine. my flame flickers... leave a plate uncovered in front of it for 15 min and wrap it up. if it stays clean then u know your hood is good
-------------------- weed gets you through times of no money better than money gets you through times of no weed... -the fabulous furry freak bros If you can buy it, you can burn it!
https://www.shroomery.org/forums/showflat.php/Number/25947396#25947396
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xmarkx
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Registered: 08/13/19
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Last seen: 2 years, 16 days
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Re: Laminar flow flame test [Re: TedsDead]
#26617772 - 04/21/20 01:13 PM (3 years, 9 months ago) |
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Hi there dear hive mind!
I also finished building my flow hood recently and did the flame test with a candle. The flame had a constant bend all over the filters surface at about 45-60 degrees, but did the flickering, just as Clc420 described. I have a motor speed controller and at first the candle was almost blown out, so i dialed it down a notch. (I can make some pictures later this week if anyone is interested, and can provide the filter and blower specs as well)
So to the point now: I wanted to see if the flow is strong enough, but i prefer to avoid getting an anemometer, so i gave the agar plate test a go. I had the flow hood on for 30 minutes, and placed an open agar plate in front of the hood for 30 minutes. I also had a control agar plate in the living room.
2 days later, both the petri dishes showed growth of contamination...
So my question to the ether is: what could be the problem, and how can i identify it?
Some thoughts on what could have gone wrong: - I might have dialed the motor down too much, so flow was maybe too weak. I admit i didn't check the flame further away from the filter, just right in front of the filter. - I wore a latex glove, but no long sleeve shirt when I opened the dish, and no face mask either. I did not overcomplicate the opening of the dish though, but i don't recall the exact position of my hand (i guess downstream though...) - The petri dish was laying on a plastic ice-cream box (which i sanitized with isopropyl alcohol beforehand) approximately 7 cm (2.7 inch) above the table. The petri dish was 5 to 10 cm (2 to 4 inch) away from the filter, right at the center for 30 minutes. Bad positioning/too long time? - Faulty construction of the flow hood? The face/filter side of the box is sealed with silicone, and the filter is undamaged.
I just assume that the mistake was made by me, and that the filter is working as it should. (The filter was classified as a H14 filter - H14 > 99.995% filtration at 0.3 micrometers).
Any advice/tip/constructive though would be much appreciated!
Thank You in advance
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Zifozonke
Stranger


Registered: 03/24/19
Posts: 1,258
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Re: Laminar flow flame test [Re: xmarkx]
#26617949 - 04/21/20 02:23 PM (3 years, 9 months ago) |
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Dont buy cheap anemometer to check resistance they arent accurate (trust me ...been there done that) And while leaving dishes open in front of hoods for minutes on end is cool if they dont contaminate-it really is not a valid test according to RR Check out this post and scroll down to see what he had to say-
https://www.shroomery.org/forums/showflat.php/Number/9868847#9868847
Im sure your problem is just something small you will figure out soon.. Good luck!!
Edited by Zifozonke (04/21/20 02:25 PM)
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Clc420
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Registered: 06/24/18
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Re: Laminar flow flame test [Re: xmarkx]
#26617997 - 04/21/20 02:41 PM (3 years, 9 months ago) |
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Quote:
xmarkx said: Hi there dear hive mind!
I also finished building my flow hood recently and did the flame test with a candle. The flame had a constant bend all over the filters surface at about 45-60 degrees, but did the flickering, just as Clc420 described. I have a motor speed controller and at first the candle was almost blown out, so i dialed it down a notch. (I can make some pictures later this week if anyone is interested, and can provide the filter and blower specs as well)
So to the point now: I wanted to see if the flow is strong enough, but i prefer to avoid getting an anemometer, so i gave the agar plate test a go. I had the flow hood on for 30 minutes, and placed an open agar plate in front of the hood for 30 minutes. I also had a control agar plate in the living room.
2 days later, both the petri dishes showed growth of contamination...
So my question to the ether is: what could be the problem, and how can i identify it?
Some thoughts on what could have gone wrong: - I might have dialed the motor down too much, so flow was maybe too weak. I admit i didn't check the flame further away from the filter, just right in front of the filter. - I wore a latex glove, but no long sleeve shirt when I opened the dish, and no face mask either. I did not overcomplicate the opening of the dish though, but i don't recall the exact position of my hand (i guess downstream though...) - The petri dish was laying on a plastic ice-cream box (which i sanitized with isopropyl alcohol beforehand) approximately 7 cm (2.7 inch) above the table. The petri dish was 5 to 10 cm (2 to 4 inch) away from the filter, right at the center for 30 minutes. Bad positioning/too long time? - Faulty construction of the flow hood? The face/filter side of the box is sealed with silicone, and the filter is undamaged.
I just assume that the mistake was made by me, and that the filter is working as it should. (The filter was classified as a H14 filter - H14 > 99.995% filtration at 0.3 micrometers).
Any advice/tip/constructive though would be much appreciated!
Thank You in advance 
Having a petri dish infront of a flow hood for 30 minutes is way too long. 30 seconds is a long time nevermind 30 mins lol. I bet if you have it open for 15 seconds it wont contam. My flow hood turned out fine for now. Not issues atm, I've had a test plate going for 2 weeks and theres nothing on it.
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xmarkx
Stranger

Registered: 08/13/19
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Last seen: 2 years, 16 days
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Re: Laminar flow flame test [Re: Clc420]
#26619994 - 04/22/20 12:42 PM (3 years, 9 months ago) |
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I was suspecting that a cheap anemometer would not give precise results (this reminds me of a saying from a good friend: "I am poor, so I buy expensive things" aka. they last longer and are better quality), plus i would only use it once i guess...so good tip there Zifozonke, and thanks for saving me from that extra round  Oh and thanks for the link to the thread, totally relevant, i just didn't find it on my own, so thanks again.
Thinking back, it does sound like a mayor overkill to expose a dish for 30 minutes. I just read a comment on a thread about flow hoods (sorry forgot where, so i can not quote it) that this person would not get contam in a dish even after 30 minutes in front of the hood. Maybe he is a pro or was exaggerating, but i went for 30 minutes as well.
I have some dishes left, so I will try another dish test. One close to the hood and one further away, both opened for 20 seconds, maybe one more for 5 seconds (as RR recommends in Zofos' thread). It is also time soon to pour some agar, and i will do it in front of the hood as well, that should give me a hint too.
I also got a nice stainless steel elevated rack, so no ice cream box next time  And i will upgrade the hood with side and top panels from plexiglass.
When i did the tests, i will post the results 
Thanks again for the tips, guys, hive mind rules!
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