Mache (unit)
Mache is an obsolete unit of volumic radioactivity named for the Austrian physicist Heinrich Mache. It was defined as the quantity of radon per litre of air which ionises a sustained current of 0.001 esu.
1 ME = 3.64 Eman = 3.64×10−10 Ci/L = 13.4545 Bq/L.
