Finally... an affordable meter for measuring sky brightness for astronomers!

The Unihedron Sky Quality Meter - L measures the brightness of the night sky in magnitudes per square arcsecond. Unprecedented sensitivity in a handheld meter!

Designed by Dr. Doug Welch and Anthony Tekatch

--Find out how good the night or site REALLY is.

--Compare the sky brightness at different sites quantitatively.

--Document the evolution of light pollution in your area.

--Set planetarium dome illumination to mimic the skies people are likely to experience elsewhere in the city.

--Monitor sky brightness through the night, night-to-night, and year-to-year.

--Determine which nights show the greatest promise for finding the '''faintest fuzzies'''!

--Calibrate the effect of sky brightness on qualitative measures such as the Bortle Scale.

--Investigate how sky brightness correlates with the solar cycle and month-to-month sunspot activity.

--Help provide local ground truth for future sky brightness prediction with the Clear Sky Clock.

--CCD users can make a correlation between the SQM reading and when the background reaches some ADC level.

• Audible signal while measurement is in progress.

   

   

• Sky brightness displayed in visual magnitudes per square arcsecond.

   

   

• Infrared blocking filter restricts measurement to visual bandpass.

   

   

• Temperature in both Celsius and Fahrenheit as well as model number and serial number can be displayed with different button press sequence.

   

   

• Precision readings at even the darkest sites.

   

   

• Power-saving features designed in for maximum battery life.

   

   

• Reverse battery protection.

The Half Width Half Maximum (HWHM) of the angular sensitivity is ~10 degrees. The Full Width Half Maximum (FWHM) is then ~20 degrees. The sensitivity to a point source ~19 degrees off-axis is a factor of 10 lower than on-axis. A point source ~20 degrees and ~40 degrees off-axis would register 3.0 and 5.0 magnitudes fainter, respectively.

Operates from 9V battery (included).

Size 3.6 x 2.6 x 1.1 in.

Maximum light sampling time: 80 seconds.

Specifications are subject to change without notice.