Frequently Asked Questions
Purchase and Usage Outside the United States
The Speck measures and reports on particulates in the air, with estimates in both particulate count and weight. In select locations, the Speck will also display the outdoor air quality as reported by the nearest regulated, federal PM2.5 station.
Each Speck is individually calibrated and uses machine learning to maximize accuracy, both of which are major improvements on most other devices.
In addition, the Speck has a full-color screen built-in, designed to sit in your house and show you second-by-second trends in air quality. This is very important because you can then develop an intuition for how your house performs; for example, when the gas heat turns on, when you cook, when you vacuum, etc. How different activities and events affect your air quality will become immediately apparent, and our online guidance then helps you understand how to significantly improve your home air quality.
Another key distinguishing feature of the Speck is related to data ownership—your Speck data belong to you! You have the power to view, analyze and share that information as you see fit. We offer an optional data repository to facilitate data collection, but never assume ownership of your information.
The Speck is Wi-Fi enabled so you can direct all your data reports to an open-source data repository where you can view and interact with your data. You can also download your data for further analysis.
Finally, many companies have announced air quality sensors that will come out over the next two years. We're pledged to buy multiples of every one of them, test them transparently and reproducibly, and publish the results. We are also inviting all air quality sensors to house their data on our open-source repository, where the customer has complete control over their data.
It is useful for anyone elderly, anyone with heart conditions, anyone with asthma, and anyone that lives in an urban environment, given how bad air can be and how we can unknowingly have filters that do not work correctly in our home! So, the Speck can be useful for everyone.
In addition, prolonged exposure to polluted air could accelerate the onset of lung disease, heart disease and allergies. Monitoring and controlling your indoor air quality is the first step towards mitigating your risks. Many people neglect their indoor air filters and don't realize how their indoor air quality is affected. With the Speck, you have instant insight to your personal fine particulate pollution exposure.
The Speck is developed mainly for indoor use. While you can put it outdoors—for instance on a covered porch or in a garage—there are many outdoor variables that can impede the Speck's function. For example, it will lose accuracy when humidity levels are very high (e.g. thick fog or during a rainstorm) or if anything obstructs the air intake (e.g. if a spider crawls in).
We will be working on calibrating and designing units that are more effective for outdoor use, and possibly even changing the enclosure for that case. However, that model is still months away.
Once you receive your Speck, you should not need to adjust the calibration yourself. If there are any firmware/software updates, we will be able push those remotely to your unit via a Wi-Fi connection.
For maintenance, our two main recommendations are:
- Keep the Speck away from direct sunlight exposure
- Clean/dust the sensor lens every 2 to 3 months by running compressed air through the air intake at the bottom of the unit
We do not anticipate you will need to do much more outside of these suggestions, but will definitely keep you informed if any changes occur.
Outdoor air quality readings on your Speck's screen require your Speck to be Wi-Fi configured for data uploads, geolocated, and within 40 kilometers of a regulated, federal PM2.5 station in our database. This feature is currently only available to those who live in the United States and some parts of Canada and Mexico. For a map of all federal stations currently in our database, please see the Public Data page, and uncheck the "Outdoor Specks" and "Indoor Specks" checkboxes.
If you know of an online source for federal PM2.5 data outside the USA, and/or are interested in helping us expand our database of federal data, please email us at email@example.com.
The Speck operates at an input voltage of 5V DC (via USB plug). The Speck comes with a USB power adapter for North American power outlets. For users outside of North America, please see the question about using the Speck with a power converter.
The Speck uses a USB micro plug for power, so you can plug it into any wall outlet as long as you have a transformer to USB. We recommend using a USB port or adapter capable of sourcing at least 500mA for maximum reliability. You can also power the Speck by plugging it into a computer; you will need to do this when registering the Speck and configuring it to your wireless network.
The Speck records temperature and fine particulate levels only. Particulates can be measured inexpensively and reliably, and, as you know, they are also a very important part of indoor air issues, since they are connected to such a large array of diseases; so, we start here.
There are devices that measure CO or CO2, but do not offer a full picture of air quality; CO is a deadly gas; and CO2 gives you a sense of how stale the air is. VOCs, on the other hand, are important to monitor to gauge air quality, because they are important factors for long-term cancer risk. However, there are no available inexpensive VOC sensors that are reliable long-term. We are still looking, and when we find one we'll certainly make it available.
If you view the Speck's data on the web site, or by downloading/exporting as a CSV, you'll see three values all related to particle measurement:
- Raw Signal or
- Particles Per Liter or
- Particle Concentration or
To begin with, the actual value coming from the Speck's dust sensor is the Raw Signal value, which
raw_particles in the CSV. And that
raw_particles name is a little
misleading. It's not actually reporting a number of particles, but rather the average time the sensor's
detection pin is pulled low in ten-thousandths of a second (per second, averaged over the sampling
interval) by particles with a size of roughly 2 microns. This raw value is the input for the algorithm
we use to produce the Particles Per Liter value.
The Particles Per Liter value is a count-based concentration--the number of particles per liter of
air (ppl). We compute this value from the raw signal value using an algorithm which was tuned to produce
results close to what we get from a professional-grade sensor which outputs values in ppl (the one to
which we calibrate all Specks). This Particles Per Liter value is named
particle_count in the CSV. This value is visible on the Speck's screen when the Speck is
in "counts mode" — you'll see a small "c" next to the value when the Speck is in counts mode.
Finally, the Speck also reports a Particle Concentration, which is based on an estimate of particle weight (or, more strictly, mass) where the units are micrograms per cubic meter of air (μg/m3). This value is a bit of a guess. It's a simple linear scalar applied to the count-based concentration (Particles Per Liter) to try to get the Speck to report similar PM2.5 numbers to one of the professional monitors against which we're calibrating. So, like Particles Per Liter, it's also a concentration, but mass-based, not count-based. The important takeaway is that Particle Concentration is a best guess, and won't (can't!) be perfect since the Speck is measuring particles moving across its light sensor which can only give us approximate size but tells us nothing about the mass of the particles. This value is visible on the Speck's screen when the Speck is in "weight mode" — you'll see a small "w" next to the value when the Speck is in weight mode.
This letter indicates whether the Speck is currently displaying its particle measurement as count-based concentration or a weight-based concentration. The Particles Per Liter value is the count-based concentration, and so the Speck displays a c next to the value. The Particle Concentration value is the weight-based concentration (or, more strictly, mass), and so the Speck displays a w next to the value. You can toggle between the two units by tapping the value on the Speck's screen.
For more information, please see the question about the difference between Raw Signal, Particle Count, and Particle Concentration.
No, it does not. The Speck has enough memory on-board for nearly 2 years of measurements. Once you do connect it to Wi-Fi and register it with specksensor.com, it will report any saved data samples up to your specksensor.com account. However, you could also use it as an entirely standalone device; the Speck screen makes that very effective, since you will see instant air pollution values as well as historical trends right on the screen!
Even if you choose not to register your Speck to upload its data to specksensor.com, you should still connect it to a Wi-Fi network, if possible. The Speck uses its Wi-Fi connection to correct its internal clock and download firmware updates.
Yes! Your data is exactly that—your data. Our Speck Chrome app provides a way to download data directly from the Speck to a computer, saving it to a CSV file. We provide this capability for users who choose not to configure their Speck to upload to our data repository. Alternatively, the Chrome app is open source, so users with programming knowledge are free to write their own tools to download the data if they wish.
Regardless of whether you download data directly from the Speck using our Speck Chrome app, or export the
data from the specksensor.com web site, the data will be saved as a CSV file. The first field in the CSV
file is the timestamp for when each data sample was recorded. It will either be named
EpochTime, but in both cases simply represents the
number of seconds that have elapsed since 00:00:00 Coordinated Universal Time (UTC) on Thursday, 1
January 1970, not counting leap seconds. This system for representing time is also commonly known as
Unix Time, POSIX Time, or Epoch Time. For the Speck data files, the timestamp value will typically be an
integer, but, in general, it can have a decimal component to represent fractional seconds (thus, when
using it in code, you should treat it as a double, not an integer).
var date = new Date(1000 * 1442470597)
And then, printing it out with
date.toString() would return:
Thu Sep 17 2015 02:16:37 GMT-0400 (EDT)
For users using Excel, it takes slightly manual conversion, but it's still easy. For example, if there's a Unix Time value in cell A2, then this formula will convert to an Excel date:
This behavior sounds like the internal clock battery has gone dead, and this causes the software on the Speck to report abnormally and stay at 0. You can fix this problem can by replacing the 1225-size coin battery using these instructions.
Purchase and Usage Outside the United States
Sorry, currently, no. Although you can see public Specks from anywhere in the world on the Public Data page's map, at this time the search for nearby regulated air quality monitors only draws from our database of federal monitors within the U.S. (and a handful in Canada and Mexico). Thus, the search feature won't return air quality data for most locations outside the U.S.
However, if you know of a good source for air quality data from another country, please email us at firstname.lastname@example.org and let us know. We would certainly love to expand our database to include other countries!