Picture(s) thanks: 0
Results 1 to 15 of 26
Thread: Guess the dust level
-
22nd June 2020, 04:06 PM #1.
- Join Date
- Feb 2006
- Location
- Perth
- Posts
- 27,787
Guess the dust level
Was at a mens shed this morning doing a consult and decide to take a few readings with a dust meter.
In the machine room there were two blokes = one thicknessing 2 X 1.5" Short piece of timber, the other shaping a block using a large belt sander.
Each machine was hooked up by 4" flexy to its own 2HP DC , both inside the same room.
They had only been going for a couple of minutes (it was about 8:45 am) when I took the reading.
Dust meter is hanging from a suspended GPO as show by blue arrow.
As you can see there were other machines in the same room
IMG_4410p.jpg
Guess the PM2.5 (in µg/m^3) dust level?
For reference
< 12 is Good
< 35 is unhealthy for sensitive groups
< 56 Unhealthy
<150 is VERY unhealthy
<250 is hazardous
The values are of course for constant exposure - for short term exposure the levels are moved up one on the health scale.
-
22nd June 2020 04:06 PM # ADSGoogle Adsense Advertisement
- Join Date
- Always
- Location
- Advertising world
- Posts
- Many
-
22nd June 2020, 04:20 PM #2GOLD MEMBER
- Join Date
- Mar 2018
- Location
- Sydney
- Posts
- 1,166
this is a rhetorical question, right BobL ?
I'm guessing over 250. There's good evidence of settled dust (the broom) but they also have a room ventilator so that might keep things a bit better - if it's on
-
22nd June 2020, 05:00 PM #3.
- Join Date
- Feb 2006
- Location
- Perth
- Posts
- 27,787
Somewhat surprisingly, not that high - remember they had only been making dust for maybe two minutes before I took the reading.
Ventilator was not on, but after asking the supervisor if I could take a photo (I had already taken the dust level reading) he turned the ventilator on.
I wish I could have hung around to see if it had an effect. Unfortunately I had to leave but I may be going back.
-
22nd June 2020, 05:09 PM #4GOLD MEMBER
- Join Date
- Mar 2018
- Location
- Sydney
- Posts
- 1,166
-
22nd June 2020, 06:11 PM #5.
- Join Date
- Feb 2006
- Location
- Perth
- Posts
- 27,787
I'm not pretending this was any sort of proper testing sequence. The shed had just opened (it had been closed all weekend so I knew the dust level would be low to very low) when the shed supervisor and I walked into the main machine section of the shed. I noticed DCs and machines and a layer of dust over everything - not that different to many mens sheds. The supervisor and I started about dust extraction and these two blokes walked holding pieces of wood. The noise was a bit much so we walked as far from the noise we could and kept talking. As I had a dust meter on me after a couple of minutes I decided to turn it on. The Supervisor saw the level and then turned on one of the 2 room air filters.
-
22nd June 2020, 07:10 PM #6SENIOR MEMBER
- Join Date
- Feb 2016
- Location
- Perth WA Australia
- Posts
- 829
I'm having a stab in the dark, but would have said between 100-150.
Would be very interesting to see a full days worth of data.
-
22nd June 2020, 10:27 PM #7GOLD MEMBER
- Join Date
- May 2011
- Location
- Albury
- Posts
- 3,034
If there's no prize for guessing the number of jelly beans in the jar what is the point of this thread.
-
22nd June 2020, 10:36 PM #8.
- Join Date
- Feb 2006
- Location
- Perth
- Posts
- 27,787
The amount was 48 µg/m^3 at the sampling point and was still going up when I stopped measuring.
It's not as bad as I thought it was going to be
BUT
It would have been off a very low base - shed had not been used for two whole days so dust settles out
It involved just couple of minutes of dust making activity.
It would have been interesting to see how it changed in time especially with etc RAF on.
-
23rd June 2020, 01:18 AM #9GOLD MEMBER
- Join Date
- Aug 2007
- Location
- Saskatoon, SK, Canada.
- Posts
- 1,439
While the dust levels in the room at waist high read on the verge of unhealthy the boys are sucking in a lot worse with their noses right over the machines even if only for a short time. Seeing what the levels were like over the course of the day, or even better the week would be more telling. It is interesting to see that the reading came from a presumed near zero to 48 in a just a few minutes. Bob did it look like the dust was escaping from the machines or from passing through the dust pumps? The puff from the DC's being turned on.
Pete
-
23rd June 2020, 09:04 AM #10.
- Join Date
- Feb 2006
- Location
- Perth
- Posts
- 27,787
Yep. The reason for detector location was its a bit of a gamble putting basic dust detectors too close to dust sources.
Seeing what the levels were like over the course of the day, or even better the week would be more telling.
It is interesting to see that the reading came from a presumed near zero to 48 in a just a few minutes. Bob did it look like the dust was escaping from the machines or from passing through the dust pumps? The puff from the DC's being turned on.
-
23rd June 2020, 09:48 AM #11GOLD MEMBER
- Join Date
- May 2011
- Location
- Albury
- Posts
- 3,034
With, at least 2?, DE's in the shed things are never going to be good and the dust levels at the end of a solid day of work would likely be right up there. I couldn't count the number of times you've said that the most important first move is to get the DE out of the shed, Bob. No doubt you'll be setting them on the right track, hopefully they have the readies to quickly incorporate the most immediate requirements.
-
23rd June 2020, 10:23 AM #12.
- Join Date
- Feb 2006
- Location
- Perth
- Posts
- 27,787
Yep, but its a bit of a toss up as to what they can/should do in the short term. They're located on the grounds of high school so just moving their DCs outside is not going to happen plus they're moving to a new shed by years end and will be getting a new large Felder? DC. What they really wanted me to do was help them with their new ducting layout etc. The bloke with the plans was not there so I;'m getting them sent out by email.
-
23rd June 2020, 08:42 PM #13.
- Join Date
- Feb 2006
- Location
- Perth
- Posts
- 27,787
Went to a coastal Mens shed this afternoon for a consult. Nice big shed - nice atmosphere.
Shed's on a bit of a rise about 3 km from the beach.
Two very large roller doors at each end of the main shed.
A fairly stiff Fremantle doc was "in".
They have Felder 200 plus several other 2 and 3HP DCS (only the 3HP is outside their shed) but all with only 100 mm ducting so a pall of fine dust settled on everything.
Given the number of machine and potential simultaneous users this was not really enough suck for their requirements.
About half their Machines are on Auto blast gates (DCs are not auto)
They have 100's of members but only about 30 members were present today.
One guy was using a disc sander, one guy was using a radial arm saw and one a TS. Two guys using routers, the rest were either in the metal work area or painting assembling.
Chips all over the place.
Outside the PM2.5 was 1 µg/m^3 inside it was was 3 µg/m^3!
Shows the power of ventilation.
Of course they are smart enough to recognise that the "Doctor" is not going to help them on still days or when winter storms come in and the have to close the rollers.
Recommendation
All DCs outside
Get 9" trunks and 6" ducting to machines happening.
Get another Felder 200 to replace all the smaller DCs
Get some BMHs going
Overall appear very receptive
-
25th June 2020, 08:13 PM #14.
- Join Date
- Feb 2006
- Location
- Perth
- Posts
- 27,787
Another mens shed visit today.
Inner suburban small shed, with 3 large roller doors - two open today.
About 20 members present, not much dust making activities happening when I turned up.
Mainly blokes using hand tools, one pen turner.
One bloke fired up the table saw between the two open roller doors and sawdust went everywhere - turned out 4" Flex connected to TS cabinet was choked.
Whoopee I though get the particle counter out but . . . . .
Stiff breeze blowing - highest dust level observed was 8 µg/m^ 3 ie stuff all.
Of course what happens when there's no breeze?
Usual probs.
2500 CFM Micronair VibraClean extractor located outside (no enclosure but very quiet ~80dB) - should be adequate for their size of shed.
Inside shed, all "Not very professionally" installed all Galv ducting - for which they paid an arm and a leg.
Lots of 4" flex in use.
Takeoff at DC is 300mm but quickly drops to 200mm and then dropping to 100mm at machines.
Recommendations
Rip out all bar short 300mm galv trunkline ducting (Ouch!)
Install 9" PVC trunkline to all parts of shed and then 6" ducting as close to machines.
Shorten lengths of 6" flex
Modify machine to accept 6" ducting.
Get some BMHs going.
Get some exhaust fans to aid with general ventilation when breeze not present
-
26th June 2020, 01:19 AM #15GOLD MEMBER
- Join Date
- Aug 2007
- Location
- Saskatoon, SK, Canada.
- Posts
- 1,439
Would you let us know what they decide to do? I'm curious to know if the follow all or some of your recommendations or just leave their sheds as is.
Pete
Similar Threads
-
Dust level measurements / clearvue update
By DomAU in forum DUST EXTRACTIONReplies: 20Last Post: 30th September 2016, 10:46 AM -
Budget level dust exposure measurements
By BobL in forum DUST EXTRACTIONReplies: 7Last Post: 29th July 2016, 05:44 PM -
Stanley Rule and Level Co no93 Spirit Level
By Sapling in forum HAND TOOLS - UNPOWEREDReplies: 2Last Post: 24th May 2010, 07:23 PM -
dust level sensor for cyclones
By JDarvall in forum DUST EXTRACTIONReplies: 0Last Post: 21st August 2008, 05:36 AM -
Entry level dust extraction
By DaveInOz in forum DUST EXTRACTIONReplies: 13Last Post: 16th January 2003, 08:53 AM