Sample analyzer with liquid aspirating unit and liquid surface detector

A sample analyzer comprising:

• a liquid aspirating unit that includes an aspirating tube configured to aspirate a liquid from a container for a sample analysis and an actuator configured to move the aspirating tube in an up direction and a down direction;
• a liquid surface detector, the liquid surface detector configured to detect a level of a liquid surface in the container;
• a memory for storing liquid level information indicating the level of the liquid surface;
• and
• a controller configured to determine whether the liquid level information is stored in the memory,
• wherein, in response to determining that the liquid level information is stored in the memory, the controller is further configured to control a speed for lowering the aspirating tube with respect to the liquid surface in the container by the actuator, wherein the speed for lowering the aspirating tube is based on the liquid level information stored in the memory, and control the liquid aspirating unit to aspirate the liquid from the container with the aspirating tube, and
• wherein, in response to determining that the liquid level information is not stored in the memory, the controller is further configured to control the liquid aspirating unit to, without aspirating the liquid, lower the aspirating tube, control the liquid surface detector to execute a liquid surface detection of the liquid surface in the container, control the liquid aspirating unit to raise the aspirating tube, and store corresponding liquid level information based on the liquid surface detection in the memory,
• wherein the controller is further configured to:
• if the liquid level information is not stored in the memory, control the actuator to lower the aspirating tube at a first speed to a predetermined height and to lower the aspirating tube at a second speed slower than the first speed from the predetermined height to execute the liquid surface detection with respect to the liquid in the container, and
• if the liquid level information is stored in the memory, acquire, based on the liquid level information stored in the memory, a speed switching height at which a lowering speed of the aspirating tube is switched, and control the actuator to lower the aspirating tube at the first speed to the acquired speed switching height and to lower the aspirating tube at a third speed slower than the first speed from the speed switching height to cause the aspirating tube to aspirate the liquid from the container.