Accelerated heavy‐ion beams used in biological and medical research are often utilized in conjunction with absorbers which lead to the fragmentation of the beam. The BERKLET, initially a two‐stage solid‐state telescope detector, was designed to make rapid, on‐line energy and linear energy transfer (LET) measurements of individual particles in a heavy‐ion beam, thus allowing characterization of fragmented beams. From data collected with the BERKLET, one is able to determine a number of important parameters. These include: residual energy and LET histograms for the full beam and for the individual Z components, relative number of particles with a given Z , and dose and track average LET's for the full beam and for the individual Z 's. Improvements to the BERKLET design and changes in data analysis are discussed and contrasted with the results of an earlier BERKLET configuration. The most notable improvements are the addition of a thin scintillation detector for improved LET measurement, a tenfold improvement in the dynamic range of the event discriminator, reported here as 1:2000, and dual high‐and low‐gain amplification of the LET signals, permitting the identification of particles with Z 's ranging from 12 down to 1.