Builtin capacity rechargeable lithium battery for extended operation and convenient power supply in a compact unit. Lithium battery voltage detection to monitor charge level and safeguard operation, helping prevent unexpected power loss. Automatic detection of zener diodes from 0.01 to 20 V, enabling quick and reliable identification of voltage references and diode behavior. Selftest with automatic calibration to verify measurement accuracy and maintain consistent performance. Infrared coding capability with infrared waveform display for analyzing, debugging, and validating IR signals. Buttonbased operation with automatic shutdowns and configurable timeout settings to optimize power usage and reliability. Use scenarios Electronics development and testing: Use the device to quickly check zener diode characteristics across the 0.01–20 V range, perform selftest calibrations to ensure accuracy, monitor the builtin lithium battery state, and analyze infrared signals during component and circuit validation. Infrared remote control development and debugging: Capture and encode infrared signals, view IR waveform displays to verify timing and modulation, and adjust code logic based on waveform analysis. Batterypowered device maintenance and monitoring: Rely on the builtin lithium battery with voltage detection to monitor remaining capacity, ensure safe operation, and use automatic shutdowns to prevent unexpected power loss during field work.