Sound meters can be useful for many different applications and purposes. For me, I wanted one to make it easier to determine whether I should wear hearing protection for a certain tool or not. While there are times when it’s obvious hearing protection is needed, other times it’s not so clear.
Most people know when they should be wearing safety glasses, but it’s a little harder to figure out when you need to wear hearing protection. For instance, is it more important to protect your ears for the hours you are mowing the lawn or the intermittent hammering of your impact driver? Or what’ll cause less long term hearing damage, a ShopVac or a proper dust collector?
Sounds of less than 75 decibels, even after long exposure, are unlikely to cause hearing loss. However, long or repeated exposure to sounds at or above 85 decibels can cause hearing loss. The louder the sound, the shorter the amount of time it takes for NIHL to happen.
DIYers and Pros will often wear hearing protection when working around noise levels that are immediately uncomfortably loud, but even if a sound isn’t loud enough to cause immediate discomfort, it could still be loud enough to potentially cause irreversible hearing damage.
We’re not really good at judging how loud a sound really is, so we need a tool like a sound level meter to measure it for us. I’ve been thinking about buying a meter for a while, and when I was looking for Craftsman tools to test, I found their 82016 Pocket Sound Meter.
We bought this Craftsman sound meter from Sears, at retail pricing.
This sound meter appears to be identical to the Extech SL10, except for the color and printing on the case. The Craftsman sound meter is also occasionally less expensive than the Extech.
The sound meter has a 1/4″-20 threaded insert on the back, so you can mount the meter on a tripod or other fixturing device. It’s powered by a single 9V battery, which is accessed by removing a cover on the back.
It’ll measure sounds in the range of 31.5 Hz to 8 kHz, and has a 125 ms response time, although the display only updates every 0.5 seconds. The meter applies an ‘A’ weighting to the sound measurement, which makes sense for a Craftsman tool, as the ‘A’ weighting is usually used in assessing industrial and environmental noise.
The Craftsman sound meter is contoured to fit in your hand with easy access to both the power and Min/Max buttons. The screen is backlit and the numbers are large and very readable. (You can’t see the backlight in the photo above because I used a flash.)
The meter is simple to use: turn it on and start taking readings. Of course, taking readings that mean something involves more thought. To really take meaningful data, like how loud a tool is, you need to know the distance from the tool, have a repeatable setup, and to be really thorough you should probably note the orientation of the meter.
Also, the manual said you should calibrate the meter before every use, but you either need an expensive calibration device or another calibrated sound meter to compare your readings. There is no way to actually adjust the reading, so all you’d be doing is a Go/No-Go test.
Taking Some Data
I’ve been using my ShopVac for dust collection, and have been thinking about getting a proper dust collector for a long time. It would be nice to have more collection power, but I also thought it would make my shop quieter, as the ShopVac is quite annoyingly loud.
An opportunity to get a dust collector arose recently, just a couple of weeks ago. A neighbor put a practically new Jet 1100CFM dust collector with filter canister out on the curb for free, so I snatched it up.
After I wrangled the behemoth into my shop and got it set up, I turned it on and it sure sounded like it was much quieter than my vacuum, but that’s not what the data I took shows.
To take the data, I set up the sound meter on a tripod at about head level where I would typically stand while working. For these measurements I waited until the reading settled down and rounded the reading to the nearest whole number.
|Table Saw (horiz)||49dBA||77dBA||80dBA|
|Table Saw (vert)||51dBA||80dBA||80dBA|
I was really surprised to see that not only was the dust collector not quieter than the ShopVac, in certain situations it could be louder. Qualitatively, the dust collector seems quieter, but maybe that’s because it emits more of a low frequency rumble compared to the ShopVac’s higher pitched whine.
These sound levels are close to the point where they could cause damage to your hearing, especially considering that a shop vacuum or dust collector will be used with other power tools.
I also tried measuring what the noise level of some of the tools I owned. For this I set the tool on my bench and set the sound meter on a tripod at the same height 3 feet away. Then I clicked the max button until “MAX” showed on the screen. What this does is show the highest db level reached. After a minute or so, I recorded the values below.
|Milwaukee M12 Vacuum||80dBA|
|Ryobi Air Grip while attached||80dBA|
|Milwaukee Impact Wrench||93dBA|
|Milwaukee Right Angle Impact wrench||97dBA|
I was quite surprised at how loud the right angle impact wrench got when I bottomed out a screw. I am definitely wearing hearing protection when I use an impact wrench from now on.
Hearing protection should be used with some of the other tools as well. Tools like the Milwaukee M12 vacuum are in the grey area between “won’t cause hearing damage” and “can cause hearing damage” with prolonged use.
I have no way of checking the calibration, so I can’t report on how accurate the Craftsman sound level meter was. It purports to be accurate within ±3.5dB. The measurements I got made sense from what I know the actual sound level should be.
I also didn’t run a formal repeatability test, but my impression was that the readings were pretty repeatable. If I measured the decibel level of something one day, under the same conditions, the reading was always within a few dB the next day.
One thing that annoyed me during testing was that the meter automatically powers off after 15 minutes of inactivity. In real life usage it probably is a good thing so you don’t drain the battery unnecessarily.
Other than that one annoyance, I found the meter intuitive to use. This probably isn’t the meter to buy if you are trying to comply with safety regulations, but it isn’t bad for somebody who’s interested in doing some noise abatement in their home or shop.
The Craftsman 82016 Pocket Sound Meter is listed at $40 on the website right now, but I’ve found the price seems to fluctuate a bit. Our purchase price was $32 in store.