Latest Deals!

Unihedron Sky Quality Meter with Lens (SQM-L)

ITEM #
UH-SQM-L

OPT Guarantee

  • Sale
  • Regular price $134.95

In Stock
Add to Wishlist
Already have gear? Trade it in for cash or new equipment.

Accessories Added

Rod, Telescope Expert

Want Help?

Just ask one of our sales reps

1.800.483.6287

Unihedron Sky Quality Meter with Lens (SQM-L)

 

Finally, an affordable meter for measuring sky brightness!

 

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

 

Uses:

  • 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 Unihedron SQM-L reading and when the background reaches some ADC level.

Features:

  • 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.

 

 

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 ~20degrees.
  • 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

ManufacturerUnihedron
Warranty1 Year Warranty

Customer Reviews

4.9 Based on 8 Reviews
5 ★
88% 
7
4 ★
12% 
1
3 ★
0% 
0
2 ★
0% 
0
1 ★
0% 
0
Write a Review Ask a Question
  • Reviews
  • Questions

Thank you for submitting a review!

Your input is very much appreciated. Share it with your friends so they can enjoy it too!

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!

A
11/13/2018
Anonymous
United States

Great dark sky meter

Really simple worked perfectly first and every time. Great for citizen science projects and also documenting sky conditions when you take astrophotos. Much more accurate than iPhone app