Hello! For flatness verification of the TDS 5052
level devil oscilloscope, you should refer to the device's service manual, which usually contains detailed procedures for calibration and verification. Additionally, Tektronix, the manufacturer, often provides technical support and documentation on their website. You might also find helpful resources and discussions in specialized forums or communities focused on oscilloscope usage and maintenance. If you need specific calibration tools or software, Tektronix support can guide you on obtaining those. Good luck!