The 1st BCM in MEBT is used to be located between Q1 and Q2 but now is attached to the flange of RFQ. At this location, the BCM signal includes the current of the unaccelerated particles included in the RFQ output and, to measure the RFQ transmission of the bunched part, an additional BCM may be required in the inital part of the MEBT. This presentation studies where in the MEBT the unaccelerated particles are completely lost and discusses options for the location of the additional BCM. Appendices include an explanation of how to include unaccelerated partilces in a calculation of Partran.