If the normal indicator (green light) is on, it means that the temperature is not overwritten during recording; If there is an alarm when the indicator light ( red light) is on, it means that the temperature is overheating while recording. How to use: 1. Press and hold the "/stop" button for more than 3s, the "OK" indicator be on for 3s, indicating the device starts recording, and then you can place the device in the environment you need to control. 2. During the recording process, the device automatically turn on the light every 10s. If the normal light (green light) is on every 10s, it means that the device does not overheat during the recording process. If the alarm indicator light ( red light) illuminates every 10 seconds, explain that excessive temperature occurred during the recording process. Note: If overheating is detected during the recording process, the green light no longer be illuminated. 3. Press and hold the /stop button for more than 3s, the alarm indicator ( red light) be on for 3s, indicating that the device stop recording. Recording also stop automatically when the device is full. After the device stops recording, it not flash automatically. If the device overheats during recording, press the /stop button. Remove the waterproof packaging bag and insert the device into the computer's USB interface. During the process of creating PDF files, the normal indicator light ( green light) and the alarm indicator light ( red light) turn on. When the file is generated, the normal light ( green light) be on until the logger is removed from the computer., Manufacturer: CTRLZS