This little sundial shows the RLT (real local time). Its precision amounts to 10 minutes which is very good for such a small item. This sundial was developed and manufactured by AlphaFluid; designed by Yves Opizzo.
It is easy to operate: First of all you have to set the corresponding date by using the small knurled screw and the date scale. The date scale is marked with signs of the Zodiac as this division very accurately follows the sun declination.
The correspondance of the months is displayed here as well as on the backside of the sundial. The 4 great symbols from mediaeval times stand for the seasons:
Winter when snow falls
Spring with a sprouting seed
Summer with an open blossom
Autumn when the flower dies and the new seed sprouts
After you have set the time, keep the sundial in the same position and turn it towards the sun until a sharp flame is visible on the grid on the front side. The point of intersection with the corresponding date line results in the RLT.
In order to get the CET (Central European Time) or CEST (Central European Summer Time) it is necessary to make a triple correction:
1. Add the hour of the summer time.
2. Correct the time difference, which occurs because of the difference of longitude of your position and the reference meridian – the meridian of Görlitz.
If you take the equation of time into consideration, the sundial is quite exeact.
3. Add the equation of time with the algebraic sign.
It is quite difficult to make this last correction, as the equation of time changes every day. You may
gather the differences from th following table.
It shows the average values of the time equation in minutes and seconds for four years at 12 o’clock
U.T. Please add the given time with the algebraic sign in order to get the zone time (calculated by
Time difference of various cities
The time relates to Central European Time (CET). That is why the results should be altered in some cases. Actually, there will be a time difference of one hour (for instance for Great Britain).
Info sheet Lux Flamma (French, français)