Magnaflux Centrifuge Tube 14A, 14AM, 20BMagnaflux 8493 Centrifuge Tube for Fluorescent MPI Bath Monitoring The Magnaflux 8493 is a 100 ml ASTM pear shaped centrifuge tube used to monitor the bath concentration and contamination level of magnetic particles in Magnaglo 14A, 14AM, and 20B fluorescent magnetic particle baths. Graduated from 0 to 1. 0 ml in 0. 05 ml increments, the 8493 provides the precise readings needed to maintain consistent bath strength and reliable inspection results.