  We measured the surface tension of linear alkylbenzene (LAB) HYBLENE 113
mixed with Diphenyloxazole (PPO) as well as of pure LAB HYBLENE 113 as part of
material studies for the liquid-scintillator based surround background tagger
(SBT) in the proposed SHiP experiment. The measurement was performed using the
iron wire method and the surface tension for linear alkyl benzene HYBLENE 113
plus PPO was found to be $(30.0\pm0.6)$ mN/m $22.0\pm 0.5$ {\deg}C and for pure
HYBLENE 113, $(29.2\pm 0.6)$ mN/m at $21.0\pm 0.5$ {\deg}C.
