FAQ - Frequently Asked Questions
Can you tell more about the history of the project?
Originally it started out in 2015 with a project to make another UV-protecting mask, but we found out that it was more urgent to have a more robust and friendlier UV-dosimeter.
The French language page Projet LUVI on the site of Enfants de la lune gives nice description of the history while an automatic translation in English of this very page may also be available or in this pdf file: Projet_LUVI___Enfants_de_la_lune.pdf.
What is the unit of measurement?
The LUVI displays the value in mMED/hr (milli-MED per hour) according to the “old” definition being 1 MED/hr = 5.8uW/cm2 (erythema weighted). The reference device that has been used by the French Enfants de la Lune before also displays in mMED/hr. Families have trusted this device for years with clinical success and therefore the LUVI also shows the value in mMED/hr.
Can you give an idea of what is a mMED/hr?
You may know the UVI, the Global Solar UV Index that you may see sometimes on weather channels that has a scale of 1 to 11, where 1 is considered "low risk" for non-XP persons. One MED/hr would be equivalent to 2.32 UVI.
One mMED/hr is one thousandth of a MED, so would be like only 0.00232 UVI. This is the UV radiation level some time after the sun goes down in the evening or some time before the sun comes up in the morning.
See also Global Solar UV Index - A Practical
Guide (also in french and spanish), on the WHO
Ultraviolet radiation site.
How can I convert from mMED/hr to UVI?
The LUVI shows readings in mMED/hr and not in UVI. If you want to make a conversion table to UVI you would need to take the reading and device and multiply by 0.00232. For example, 1000 mMED/hr -> 2.32 UVI Above a UV intensity of 1999 mMED/hr (= 4.64 UVI) the LUVI will show an overflow as [1 ].
mMED/hr LUVI reading | UVI index |
---|---|
100 | 0.23 |
200 | 0.46 |
500 | 1.16 |
1000 | 2.32 |
1500 | 3.48 |
1999 | 4.64 |
1--- | more than 4.65 |
mMED/hr LUVI reading | UVI index |
---|---|
431 | 1.00 |
862 | 2.00 |
1293 | 3.00 |
1724 | 4.00 |
I see a small B in the display, what does that mean?
Seeing a small B in the upper-left of the display means that the battery is empty. Please replace it by an identical non-rechargeable battery: 9 Volt Alkaline (PP3, IEC 6LR61). With normal use a new battery will last more than a year.
30 January 2024