An upgoing and downgoing arrangement of transducers in a logging tool, largely to offset spurious changes in reading caused by variations in borehole size or sonde tilt.

• 指换能器在测井仪器中的上、下配置方式，主要用来补偿由于井眼尺寸变化或探头倾斜所引起的测井读数的不合理变化。