Sound levels of impact driver and other common garage stuff.

The other day I was thinking about the sound levels on my new impact driver, and wondering if I should use ear plugs/muffs with it: http://www.garagejournal.com/forum/showthread.php?t=239009.

Today I remembered that I've got really old analog sound pressure meter that someone gave me years ago when I was helping them out on a job. I've hardly ever used it because it's as old as hell, and not having anything to calibrate it with, I wasn't even sure if its readings were meaningful. Anyway, despite being a bit uncertain about the equipment I decided to measure the sound levels (at the typical operator ear position) for a bunch of tool and garage related stuff. The results are listed below if this is useful to anyone else.

Normal conversation (at about 4 ft): 55 to 65 dB
Watching TV: 60 to 65 dB
Music (Background/Mood): 65 to 70 dB
Music (Solid medium listening volume): 70 to 75 dB
Vacuum Cleaner (domestic): 75 dB
Hair dryer: 75 dB
Music (Loud): 85 dB

Drill Press: 80 dB
Drill Driver (cordless): 85 dB max (in torque clutch limit)
Lawn Mower (4 stroke): 85 to 90 dB
Bench Grinder (grinding metal): 95 dB
Brush Cutter (2 stroke): 100 dB
Angle Grinder: 100+ dB
Impact driver (while impacting): 96 to 104 dB depending on speed.
Drop Saw (sawing wood): 107 dB

BTW. I also measured some mundane around the house stuff above. This was mainly to test the validity of the readings, as typical values for a lot of this stuff is available online. Overall my results ended up agreeing very closely with what data I could find online etc. So I'm pretty confident that the results are at least reasonably accurate.

Finally, I know this forum loves pics , so here's the old POS sound meter that I used for all the above measurements.

Drill Press: 80 dB - really that loud?
Drill Driver (cordless): 85 dB max (in torque clutch limit) - yeah, the clutch can be loud.
Lawn Mower (4 stroke): 85 to 90 dB - I always wear hearing protection when mowing
Bench Grinder (grinding metal): 95 dB - I always wear hearing protection when grinding
Brush Cutter (2 stroke): 100 dB - My 4 stroke is much quieter than my 2 stroke was, but I still wear hearing protection with it
Angle Grinder: 100+ dB - yeah, these are about the loudest things in my shop.
Impact driver (while impacting): 96 to 104 dB depending on speed. - doesn't feel that loud, but I'll keep that in mind
Drop Saw (sawing wood): 107 dB[/QUOTE] - yep, another dangerously loud tool

Let's see. Bench grinder, yeah, that always gets hearing protection. Table saw, chop saw, circular saw, belt sander, absolutely yes. Band saw, maybe. Fein tool, yes. Sabre saw, jig saw, no. RO sander, no, but mine are pneumatic and really quiet.
I stopped using my Snap On impact wrench, and now use an Aircat mostly, because of the major reduction in volume.

My backpack leaf blower is rated 65dB at 50 feet away. It's louder than that to the operator, but not uncomfortable, even at WOT. I found a youtube of someone measuring 100dB at WOT, but that was with the microphone right on the exhaust. The operator's ears don't experience that. When I'm cleaning up after mowing (where most of the time its in idle, and even quieter), I don't bother with hearing protection, but when I'm cleaning up leaves, I put in the ear plugs.

rlitman said:

Drill Press: 80 dB - really that loud?

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Yeah I probably should elaborate on the conditions under which some of those measurement were made.

- My drill press is a fairly cheap crappy little thing and it rattles a lot (belt may be a little loose). Surprisingly the 80 dB was the unloaded noise level, and it actually quietened down considerable once I started bearing down some pressure on it. Originally I planned to report the level of it drilling through metal, but that was actually a good 5 dB quieter. I'm sure a better quality smoother running DP would be 75 or less here. In any case, even at 80 dB it's still in the well in the safe range.

- The drill driver 85 dB was with the thing running close to flat out under torque clutch limit. Of course this isn't normal operation for this particular tool, as you'd normally release the trigger as soon as hits torque limit. So yeah, in normal operation this tool really is a lot quieter than 85.

- The bench grinder level was while doing some fairly heavy grinding, the kind of grinding you'd be doing if you had a significant lump of steel to remove. If you were just doing some light grinding to touch up an edge or something then this one could be significantly lower as well.

I got one ear fukked up from angle grinders. It took a long time, shoving a gig but in on a couple long days would have went a long way, real hard noise for any length of time for a diy is minimal in most cases, safety glasses a must.

uart said:

- My drill press is a fairly cheap crappy little thing and it rattles a lot (belt may

Click to expand...

2 phase or 3 phase motor ?

Monte said:

2 phase or 3 phase motor ?

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I think it's a single phase capacitor start Monty. Here in Australia we don't have the 120/240 split phase thing. Residential power is 240V 50Hz single phase, with the option of 415V three phase (each phase being 240V to neutral) if you need it. I've only got single phase 240V here.

I'll try to dig up a picture of it. I've never posted it in any of the DP threads here because it's too rubbish.

uart said:

I think it's a single phase capacitor start Monty. Here in Australia we don't have the 120/240 split phase thing. Residential power is 240V 50Hz single phase, with the option of 415V three phase (each phase being 240V to neutral) if you need it. I've only got single phase 240V here.

I'll try to dig up a picture of it. I've never posted it in any of the DP threads here because it's too rubbish.

Click to expand...

okay....
so it´s a universal motor with brushes ...? That add some db´s to the noise level too....

Old rattly drill press pics here. I think this thing was made by Ryobi and the model number is HBD6MA. As you can see, this poor ol' thing is pretty beat up. The belt cover is bent out of shape, rattles and it doesn't even close properly.

Monte said:

okay....
so it´s a universal motor with brushes ...? That add some db´s to the noise level too....

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No, I think it's a single phase induction motor. Induction motors can run ok on single phase, they just need some help to get started. Most use a capacitor (as this one does) to produce a phase shifted auxiliary winding in order to provide starting torque. They work best in applications where little starting torque is required, and you don't need to apply the loading until they're up to speed. Most small bench grinder motors work similarly.

Universal motors (with brushes) have the advantage of providing lot better torque at stall (or if seriously slowed under load), but they're not as simple and robust as the induction motor.

BTW. You can see the start capacitor in the second of the pictures above. It's the big bulbous thing hanging off the back of the motor on the far right side of the pic. That's not the terminal housing BTW. The terminal housing is a little rectangular shaped box on the other side (unseen in the photo) of the motor.

I've had a noise survey done on all the power tools in our shop at work. I'll have to find the report to post actual numbers.

A few things to note. Noise at 85dB, for greater than 8 hours, can cause hearing damage. This is the threshold that OSHA requires protection. However, as the noise level increases, the exposure time for damage decreases. Every 3dB is TWICE the sound energy. Adds up quick.

Even though my job doesn't require hearing protection for the type of work I'm doing, including working around helicopters (loud, but short duration typically), I choose to wear it.

The iPhone app works pretty good for general measurements. At work we have calibrated noise dosimeters...

2manytoyz said:

I've had a noise survey done on all the power tools in our shop at work. I'll have to find the report to post actual numbers

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That would be really good if you can dig it up 2many. I'd be interested to see how the numbers compare with mine.

A few things to note. Noise at 85dB, for greater than 8 hours, can cause hearing damage. This is the threshold that OSHA requires protection. However, as the noise level increases, the exposure time for damage decreases. Every 3dB is TWICE the sound energy. Adds up quick.

Click to expand...

Yeah. What I found interesting about this survey is how good my "instincts" for what is too loud actually were (before I even knew the numbers). Basically everything on my list that measures 90 dB and over were the things that I was already using ear protection with. I don't use ear muffs with the lawn mower, but basically everything louder than that I do.

I agree about time of exposure being important. I have to admit that with the bench grinder, if I'm just doing some light grinding to touch up an edge on something then I may not use anything. But if I'm doing sustained work with some heavier grinding then I always do use ear muffs.

With anything over 100 dB I like to use ear protection even if it's only for a minute.

I remember reading a few studies for some safety class about how low value, cyclic impact noise such as hammering is more damaging than a constant somewhat higher value noise.

Impact noise (hammering, gunfire, etc.) is awful on the ears, but also pretty hard to pin down to a specific db level. Most noise systems rate sound in time weighted averages, so the numbers for impact noise will be greatly deflated from their actual peak sound pressures.