... reliably measures the thickness of the poured concrete slab of non-metal like structure,concrete,wall,girder,bar,pole,wood and ceramics base ... first Range:40—350mm,Error ±1mm. Use second Range:200—600 mm,Error ±2mm; 601—800 mm,Error ±3mmData storage:45000 ... ×120mm Receive electrode:φ2550×80mmExtension Bar:φ25×600(mm)(3 piece)Work PrincipleDJLC-A concrete thickness gauge is composed of signal transmit ...