Speck Technical Specifications

The Speck air quality monitor detects fine particulate matter in indoor environments and provides information about trends and changes in particle concentration.

Speck has Wi-Fi built in, enabling optional connection to a wireless network. Once online, and after linking it with a specksensor.com account, the Speck will continuously upload its data to specksensor.com where users can see its data in real time and explore its full history with a computer or mobile device.

Detection method
Optical, DSM501A
Size range of detected particles
0.5 – 3 microns
Measurement units
ppL or μg/m3 (see Speck Measurement Scales below for more information)
Additional on-board sensor
Environmental operating range
-10 ~ +65 °C, < 95% RH without condensation
Data timestamps
Unix time via real-time clock
Sampling interval
5 seconds to 4 minutes (default 1 minute)
On-board data storage
Two years at 1 sample per minute
Online data storage
Unlimited via specksensor.com account
3.2" TFT touchscreen
Display options
On/off, brightness control, colorblind mode
USB 2.0 through Chrome app, Wi-Fi 802.11 b/g
Supported wireless encryption
Unsecured, WEP, WPA, WPA2 personal
On-screen data access
Current, past hour, or past 12 hours
Power supply
Micro USB, 5V 500mA
5.8 oz (164.4 g)
Width: 4.5 in (11.4 cm)
Height: 3.5 in (8.9 cm)
Depth: 3.7 in (9.4 cm)

Speck Measurement Scales

The Speck can display its measurement of the current concentration of fine particles in the air in two different scales. The default scale is a count-based concentration—the number of particles per liter of air (ppL). Alternatively, the Speck can report the fine particle concentration based on an estimate of particle weight (or, more strictly, mass) where the units are micrograms per cubic meter of air (μg/m3). To toggle between the two scales, simply tap the center of the Speck's screen. The chart here details the measurement scale ranges and correlation between value and color. The Speck can also display colors in a blue-red palette for colorblind users.

Particle Counts
Estimated Mass
Rating Description
8001 - 16000 321 - 640 Very High This level of particles is unsafe and warrants more serious long-term health effects if sustained.
4001 - 8000 161 - 320 High Air pollution levels are dangerous and everyone may experience coughing, itchy eyes or other symptoms. This level of particles may significantly trigger asthma and allergy symptoms. Work to decrease values as soon as possible or consider wearing a mask.
2001 - 4000 81 - 160 Elevated Air pollution is unacceptably high and problematic for all persons due to significant particulate loading in the air. Brief exposures to this level often occur from cleaning, such as vacuuming a carpet. If this level is sustained during the nighttime, consider investing in an air filter for the bedroom.
1001 - 2000 41 - 80 Slightly Elevated Air quality is problematic for vulnerable populations (elderly, respiro-compromised individuals or children). This level of pollution warrants taking steps to try to reduce: turn on your kitchen hood vent; consider opening or closing a window as appropriate, etc.
501 - 1000 21 - 40 Moderate Air quality poses a slightly elevated risk of asthma, allergy and arrhythmia symptoms. Frequently seen moderate level of particulates are often caused by human behavior (cooking, candle burning, etc.).
0 - 500 0 - 20 Good Air quality is considered good and there is little risk of particulates causing harm to your health.


Each Speck is exposed to two controlled particle concentrations, which allow us to automatically generate calibration values for each device using a networked computer system. These calibrations are performed in groups of 10, which allows for quality control implementation by removing Specks that either do not correlate well with the other sensors in the group or exhibit calibration values outside of acceptable parameters. These procedures also serve as a systems test for the sensor, Wi-Fi, screen, touch sensitivity, and fan. Each Speck is individually labeled with its coded calibration batch, serial number, and MAC address for use in diagnosing and/or isolating any unforeseen calibration errors or manufacturing defects.

Download the Speck datasheet