1 Introduction
Thank you for purchasing the SQM-LU-DL-V. You will soon be on your way to collecting scientific data.
The SQM series of products have been used in the following applications:
•
Quantitatively comparing the sky brightness at different astronomical observing sites.
•
Documenting the evolution of light pollution.
•
Setting planetarium dome illumination to mimic the skies that people are likely to experience elsewhere in the city.
•
Monitoring sky brightness through the night, night-to-night, and year-to-year for astronomical observation records.
•
Determining which nights show the greatest promise for finding the ’faintest fuzzies’.
•
Calibrating the effect of sky brightness on qualitative measures such as the Bortle Scale or NELM.
•
Investigating how sky brightness correlates with the solar cycle and month-to-month sunspot activity.
•
Helping to provide local ground truth for future sky brightness prediction with the Clear Sky Clock.
•
Helping CCD users make a correlation between the SQM reading and when the background reaches some ADC
level.
•
Assisting Sea Turtle researchers in studying the amounts of light in areas where turtle hatchlings are affected by
artificial lights.
•
Researching bird-song synchronization with dawn.
•
Researching twilight brightness changes with the addition of external Neutral Density filters. Unihedron offers
adapters to attach such filters onto the meter.
•
The SQM-LU-DL-V has the same features as the SQM-LU with the addition of data logging and vector measurement
capabilities.
The SQM-LU-DL-V appears identical to the SQM-LU-DL from the outside, the only identification is the paper label
on the bottom of the unit, and the version identification from UDM.
1.1 QuickStart
1.1.1 Setting up the instrument
1. Connect the SQM-LU-DL-V meter to the computer with the supplied USB cable. Wait for any device drivers to
automatically load (if required). You may have to visit www.FTDIchip.com to get the latest VCP drivers if they
do not get installed automatically.
2. Ensure that your computer date and time is up-to-date.
3. Install and launch UDM (Unihedron Device Manager software supplied on the CD from your File Manager).
4. Click the “Find” button to find attached devices, then click on the SQM-LU-DL-V that you connected.
5. Click ”Data Logging” tab to go to the setup page.
6. Click the “Set” button in the “Device Clock” area on that page to synchronize the SQM-LU-DL-V internal time
with your computer time and date.
7. Set the repetition time for the readings in the “Trigger” section on the left side of the window. A good rate is “every
5 minutes”.
8. Keep the SQM-LU-DL-V connected to the computer for a couple of hours to charge up the internal Supercap; this
allows it to keep the time and date clock running while you are moving from your computer to the measurement
site. A fully charged meter will keep the clock running for a few days unpowered.
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Summary of Contents for SQM-LU-DL-V
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