The last two digits are the firmware revision. Model 1.xx is the SQM, Model 2.xx is the SQM-L. This is the temperature inside the unit, not the outside temperature.

$convert clock time to degrees$

While the display is still showing something, press and hold the button and watch the following results: Also, the model and serial number are displayedįor example, press and release the button once. How can I get the model and serial number from the SQM or SQM-L? The temperature in degrees Celsius then degrees Fahrenheit are displayed when you press and hold the button a second time. Try replacing the battery with a fresh one. Meter makes a quiet clicking noise instead of providing a reading. If you intend on just connecting the unit to a laptop rather than a network, an Ethernet crossover cable can be used. The SQM-LE has the same optics as the SQM-L as well as a computer interface via an Ethernet connection. These models have a minimum of components to reduce costs, and they cannot communicate with a PC. No, the SQM and SQM-L do not have an external port.

Note: The SQM-LE has the same optics as the SQM-L.ĭoes the SQM or SQM-L have an external port that can be connected to a PC? Then the regular SQM will do fine for that task. If you expect to always take readings at dark sky sites in an open field Trees do not affect the reading very much. It hasĪ lens to narrow the field of view so that street lights and buildings or The SQM-L is better suited for astronomy and dark sky enthusiasts. Generally speaking, the SQM-L 'Half Width Half Maximum' is ~10ĭegrees as opposed to ~42 degrees for the SQM. The SQM spec for field of view is located in this technical report.Ī comparison of the angular response for both meters is here. The lens collects more light from a smallerĬone so that the meter is not affected from lights or shading on the horizon. The main difference is the field of view. Here is a chart showing the differences at a glance. SQM & SQM-L Questions What is the difference between the SQM and SQM-L? Press and release the button, when the beeping stops, then you can turn The same side as the display, so you will aim the display at the sky and What if the SQM is reading too dark (reading 23 or 24)?Įnsure that the sensor is aimed at the sky. Hardware would be necessary, significantly increasing the cost of the TheĪdoption of a different solid angle would require a fixed zeropointįor equivalent sensitivity at a smaller solid angle, a lens and mounting Our design offers the maximum flexibility and customizability. It is straightforward to reduce this solid angle with a mask,īut different observers have different preferences for beam size and so The part of the sky where people would normally be observing and Sensitivity and partly to be representative of the sky conditions over We picked the large solid angle of the detector partly for greatest How was the solid angle of the detected light chosen? Representative of the range of altitudes over which observers Hardware would have been required and this would have dramatically To produce a spot meter, a fast lens and mounting On the sky (we measured the effective solid angle to be 1.532 It is worth pointing out that this is not a 'spot' meter - itĪccepts light from a wide cone - roughly 80 degrees diameter The 'effective solid angle' is 1.532 steradians. SQM Questions What is the field of view for your device? See FOV comparison chart.

Convert clock time to degrees