... separated measuring unit and control unit for easy operation. 2.Large LCD screen,English interactive menu, Main Features and ... , separated measuring unit and control unit for easy operation.2.Large LCD screen, English interactive menu, with opacity reading ... 20%(abs.)Revolving Speed (piezoelectric ): ±1.0% (rel.)Oil temperature : ±2°C(abs.)3.Effective Length of Optical Path : 215mm4.Equivalent Length ...