Unihedron SQM-L Sky Quality Meter with lens
$269.95
Discontinued Product
[Alert me when back in stock]
Description
Offers a more narrow field of view than the SQM.
An affordable meter for astronomers wanting to measure their sky brightness.
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 predictions.
- CCD users can make a correlation between the SQM 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:
- The Half Width Half Maximum (HWHM) of the angular sensitivity is ~10°. The Full Width Half Maximum (FWHM) is then ~20°. The sensitivity to a point source ~19° off-axis is a factor of 10 lower than on-axis. A point source ~20° and ~40° 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.
User comments
“Gives plausible readings every time. Darkest so far has been 23.05 Mag/arcsec2 in my unlit bedroom. Outdoors I get 15.93 with a streetlight on and 19.55 with it off. It really does need a clear sky on a moonless night to get proper readings, so I’m still waiting for some real results.” – Bryan
Questions? Call us on 1300 ASTRODOG or just use the form!
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Additional information
| Weight | .5 kg |
|---|---|
| Dimensions | 22 × 9 × 10 cm |








