Detecting device for test tube sample capacity

The utility model discloses a detecting device for the test tube sample capacity. The detecting device comprises a main controller, a sampling needle, a sampling needle fixing frame, a test tube and a test tube frame, wherein the test tube is used for containing a sample, and the test tube frame is used for bearing the test tube. The main controller is connected with a sampling needle fixing frame driving mechanism and a test tube frame driving mechanism in a control mode, and when the test tube moves to the space below the sampling needle, the center line of the sampling needle coincides with the center line of the test tube. The detecting device further comprises a liquid level sensing circuit board, and the liquid level sensing circuit board comprises a capacitive sensing driving circuit, an analog signal processing circuit and a level signal circuit in a sequential connection mode. The sampling needle is made of electric conduction material. The upper portion of the sampling needle is fixed to the samplin