Unihedron Sky Quality Meter - LU (SQM-LU)

Unihedron Sky Quality Meter - LU

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 SQM reading and when the background reaches some ADC level.

Features:

• Sky brightness reported in visual magnitudes per square arcsecond.
• Infrared blocking filter restricts measurement to visual bandpass.
• Sensor temperature, model number, and serial number are provided.
• Precision readings at even the darkest sites.
• Field-upgradeable firmware.
• Open protocol document.

Weatherproof Housing

This housing design is made to protect the SQM-LE/LU from normal outdoor conditions including weather and insects.

Features:

• White surfaces reflect the hot summer sunshine.
• Opening on bottom to allow moisture to escape.
• Glass top to prevent scratching when removing ice.
• Raised glass surface to prevent dirt and leaves from collecting.
• Small glass opening to minimize internal heating due to the Sun.
• Cable opening at bottom sealed with open-cell (breathable) foam prevents insects from entering.
• Marine silicone seal rated for outdoor use.
• Silicone seal around glass extends beyond glass-plastic interface to prevent ice from building in crevices.
• Hose clamps for easy mounting to pole.
• Staples for easy mounting to wood surface.

Details:

• Diagram of all SQM meters that fit into housing (PDF)
• Photos
• Glass versions (PDF)
• SQM-LE wiring layout inside housing.

What you get:

• Housing with removable top cap. 8.8 x 18.7cm, 360g.
• Two adjustable clamps.
• Two staples for mounting to wood.
• Instruction sheet.
• An optional PoE (Linksys WAPPOE-5V or D-Link DWL-P200 or TL-POE200) for extended length SQM-LE installations.

Technical Specifications

• USB connectivity
• Included applications for reading data in Perl.
• 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. Annotated FOV spec.

Comparison chart

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• Size 3.6 x 2.6 x 1.1 in.
• Maximum light sampling time: 80 seconds.
• Minimum light sampling time: 1 seconds.
• Specifications are subject to change without notice.

In the Box

• Unihedron Sky Quality Meter - LU

Meter only

SQM-LU unit USB flash drive containing the users manual, operation software (UDM), and example software. This can also be found online. 15ft USB cable Calibration sheet indicates unit USB serial number, and calibration values

Meter and weatherproof housing

SQM-LU unit USB flash drive containing the users manual, operation software (UDM), and example software. This can also be found online. 15ft USB cable Calibration sheet indicates unit USB serial number, and calibration values Weatherproof housing

Warranty & Manual

Warranty: Unihedron Warranty