{"id":2437,"date":"2012-10-18T14:21:12","date_gmt":"2012-10-18T14:21:12","guid":{"rendered":"https:\/\/www.geoptik.com\/?product=sky-quality-meter-lu-dl"},"modified":"2026-02-05T10:31:41","modified_gmt":"2026-02-05T10:31:41","slug":"sky-quality-meter-lu-dl","status":"publish","type":"product","link":"https:\/\/www.geoptik.com\/en\/prodotto\/sky-quality-meter-lu-dl\/","title":{"rendered":"Sky Quality Meter LU-DL"},"content":{"rendered":"<p><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\"><b>A USB enabled data-logging light meter for night-time sky brightness monitoring!<\/b><\/span><\/span><\/span><\/span><\/p>\n<p><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">An affordable meter for continual, connected or autonomous data-logging to measure sky brightness for astronomers and light pollution investigators.<\/span><\/span><\/span><\/span><\/p>\n<p><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">The &#8220;Sky Quality Meter &#8211; LU-DL&#8221; (SQM-LU-DL) measures the brightness of the night sky in magnitudes per square arcsecond.<\/span><\/span><\/span><\/span><\/p>\n<p><span style=\"font-size: 20px;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\"><b>Uses:<\/b> <\/span><\/span><\/span><\/span><\/span><\/p>\n<ul>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Measuring the night sky brightness during remote biological field experiments.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Find out how good the night or site REALLY is.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Compare the sky brightness at different sites quantitatively.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Document the evolution of light pollution in your area.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Set planetarium dome illumination to mimic the skies people are likely to experience elsewhere in the city.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Monitor sky brightness through the night, night-to-night, and year-to-year.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Determine which nights show the greatest promise for finding the &#8216;faintest fuzzies&#8217;!<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Calibrate the effect of sky brightness on qualitative measures such as the Bortle Scale.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Investigate how sky brightness correlates with the solar cycle and month-to-month sunspot activity.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Help provide local ground truth for future sky brightness prediction with the <span style=\"color: #0000ff;\">http:\/\/www.cleardarksky.com<\/span><\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\"><a title=\"Charge-Coupled Device (type of image sensor)\"><strong>CCD<\/strong><\/a> users can make a correlation between the SQM reading and when the background reaches some <a title=\"Analog-to-Digital Converter\"><strong>ADC<\/strong><\/a> level.<\/span><\/span><\/span><\/span><\/li>\n<\/ul>\n<p><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\"><b>Features:<\/b> <\/span><\/span><\/span><\/span><\/p>\n<ul>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Sky brightness reported in visual magnitudes per square arcsecond.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Infrared blocking filter restricts measurement to visual bandpass.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Sensor temperature, model number, and serial number are provided.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Precision readings at even the darkest sites.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Field-upgradeable firmware.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Open protocol <a href=\"http:\/\/unihedron.com\/projects\/darksky\/cd\/SQM-LU-DL\/SQM-LU-DL_Users_manual.pdf\"><span style=\"color: #0000ff;\">document<\/span><\/a><span style=\"color: #0000ff;\">.<\/span><\/span><\/span><\/span><\/span><\/li>\n<\/ul>\n<p><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font-size: 20px;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\"><b>Specifications:<\/b> <\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n<ul>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">USB connectivity<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Included applications for reading data in Perl.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">The Half Width Half Maximum (HWHM) of the angular sensitivity is ~10\u00b0. The Full Width Half Maximum (FWHM) is then ~20\u00b0. The sensitivity to a point source ~19\u00b0 off-axis is a factor of 10 lower than on-axis. A point source ~20\u00b0 and ~40\u00b0 off-axis would register 3.0 and 5.0 magnitudes fainter, respectively.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Size 5.5 x 2.6 x 1.1 in.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Maximum light sampling time: 80 seconds.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Minimum light sampling time: 1 seconds.<\/span><\/span><\/span><\/span><\/li>\n<li><span style=\"font-size: 16px;\"><span style=\"font-family: verdana,geneva,sans-serif;\"><span style=\"font: .9em sans-serif;\"><span style=\"font: .9em sans-serif; color: #000000;\">Specifications are subject to change without notice.<\/span><\/span><\/span><\/span><\/li>\n<\/ul>\n<p><span style=\"font-size: 14px;\"><strong>What you get:<\/strong><\/span><\/p>\n<table>\n<tbody>\n<tr>\n<td valign=\"top\"><a href=\"http:\/\/unihedron.com\/projects\/sqm-lu-dl\/whatyouget.jpg\"><img loading=\"lazy\" title=\"What you get\" src=\"http:\/\/unihedron.com\/projects\/sqm-lu-dl\/whatyouget-icon.jpg\" alt=\"\" width=\"192\" height=\"100\" border=\"0\" \/><\/a><\/td>\n<td>\n<ul>\n<li>SQM-LU-DL unit<\/li>\n<li>SQM-LU-DL users manual<\/li>\n<li>CD with PDF manual and example software<\/li>\n<li>15ft USB cable<\/li>\n<li>Battery-to-USB adapter with 6 AA cells and battery holder<\/li>\n<li>Calibration sheet indicates unit USB serial number, and calibration values<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<p><span style=\"font-size: 16px;\"><strong><span id=\"result_box\" class=\"short_text\" lang=\"en\"><span class=\"hps\">Comparison<\/span> <span class=\"hps\">Models<\/span><\/span>:<\/strong><\/span><\/p>\n<p><img loading=\"lazy\" src=\"http:\/\/www.geoptik.com\/image\/data\/Comparazione4.jpg\" alt=\"\" width=\"811\" height=\"616\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>A USB enabled data-logging light meter for night-time sky brightness monitoring! An affordable meter for continual, connected or autonomous data-logging to measure sky brightness for astronomers and light pollution investigators. The &#8220;Sky Quality Meter &#8211; LU-DL&#8221; (SQM-LU-DL) measures the brightness of the night sky in magnitudes per square arcsecond. Uses: Measuring the night sky brightness [&hellip;]<\/p>\n","protected":false},"featured_media":2436,"comment_status":"open","ping_status":"closed","template":"","meta":[],"product_cat":[118],"product_tag":[],"_links":{"self":[{"href":"https:\/\/www.geoptik.com\/en\/wp-json\/wp\/v2\/product\/2437"}],"collection":[{"href":"https:\/\/www.geoptik.com\/en\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/www.geoptik.com\/en\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/www.geoptik.com\/en\/wp-json\/wp\/v2\/comments?post=2437"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.geoptik.com\/en\/wp-json\/wp\/v2\/media\/2436"}],"wp:attachment":[{"href":"https:\/\/www.geoptik.com\/en\/wp-json\/wp\/v2\/media?parent=2437"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/www.geoptik.com\/en\/wp-json\/wp\/v2\/product_cat?post=2437"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/www.geoptik.com\/en\/wp-json\/wp\/v2\/product_tag?post=2437"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}