Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Boxplots of the (a) AC and (b) logBSC for P4 and P6 measured using the reference phantom technique with P2 as the reference and those independently calibrated in September 2015 and June 2016. Each calibration represented the average of repeated calibrations performed by multiple operators. The reference phantom technique results were grouped with sonographer and transducer on the same graph.
