Complex sentence: PGNAA and LIBS enable analysis of sulfur and ash (the latter, by summing the ash constituents), and when combined with a second type of analyzer--the moisture meter--provides moisture and energy value as well.
Split into simpler sentences: PGNAA and LIBS enable analysis of sulfur and ash (the latter, by summing the ash constituents). When combined with a second type of analyzer, the moisture meter, they provide moisture and energy value as well.