Unihedron Sky Quality Meter with Lens (SQM-L)

ITEM #
UH-SQM-L
  • An affordable meter for measuring sky brightness!
  • Unprecedented sensitivity in a handheld meter!
  • Measures the brightness of the night sky in magnitudes per square arcsecond.
  • Designed by Dr. Doug Welch and Anthony Tekatch.

 

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  • Regular price $134.95

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Unihedron Sky Quality Meter with Lens (SQM-L)

The Sky Quality Meter-L measures how clear the night or site is. Compare the sky brightness at different sites with measured results! If you're a CCD use, you can make a correlation between the Unihedron SQM-L reading and when the background reaches some ADC level.

How to Use the Sky Quality Meter-L

  • Keep track of the evolution of light pollution in your area.
  • Set planetarium dome illumination to mimic the skies you are likely to experience elsewhere in the city.
  • Monitor sky brightness through the night, night-to-night, and year-to-year.
  • Determine which nights are the greatest for finding the faintest of lights.
  • 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.

Features of the Sky Quality Meter-L

  • Receive audible signals while measurement is in progress.
  • The sky brightness measure is displayed in visual magnitudes per square arcsecond.
  • Its infrared blocking filter restricts measurement to its visual bandpass.
  • Temperature is measured in both Celsius and Fahrenheit.
  • The model number and serial number can be displayed with different button press sequences.
  • Receive precision readings at even the darkest sites.
  • Its power-saving features provide maximum battery life.
  • Reverse battery protection.

    Full List of Specifications for the Sky Quality Meter-L

    • 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 inches
    • Maximum light sampling time: 80 seconds
    • Specifications are subject to change without notice.

    OPT Product Number: UH-SQM-L 

     

    SPECIFICATIONS

    Warranty1 Year Warranty
    Customer Reviews
    4.9 Based on 9 Reviews
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    A
    05/15/2020
    Anonymous
    United States United States
    Excellent product...

    I always wondered how dark the sky was where I live. The maps always said that I was living in a rural sky but now with this device, I was able to get a true reading on the Bortle scale of usually over 21.60...much darker than I realized. By measuring the sky before I pull out my telescope, I can get a very good preview of the night viewing. The sky quality meter has proven to be worth ever penny.

    LW
    07/16/2019
    Lei W.
    United States United States
    Works as expected

    easy to use, values fairly consistent.

    HP
    03/11/2019
    Helen P.
    United States
    Unihedron Sky Quality Meter with Lens (SQM-L)

    Excellent: I would definitely buy from you again.

    DG
    03/11/2019
    Danny G.
    United States
    SQM-L Very Good Product

    This was shipped promptly and received a couple of days later. It appears to be a very good unit, simple to use and appears to provide consistent readings. Not much more you can ask for.

    JS
    01/29/2019
    James S.
    United States
    Great Opportunity

    This device is easy to use and a great way to accurately determine sky conditions for planning targets for viewing at our public observatory.

    DO
    01/17/2019
    Doug O.
    United States
    SQM Review

    Great device, easy to operate, even came with batteries!