Term used to describe a low-pressure mercury arc possessing a fluorescing layer, which emits in the
UV-A region (from \(315\) to \(400\ \text{nm}\)).
Source: PAC, 2007,
79, 293. (
Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 440 [
Terms] [
Paper]