A positive displacement pump (1) is equipped with a pump cylinder (2), a pump piston (7), a cylinder space (9), a pressure sensor (10), and a pressure channel (12). A main portion (13) of the pressure channel (12) extends parallel to a longitudinal axis (3) of the pump cylinder (2), for providing fluidic connection between the cylinder space (9) and the pressure sensor (10). In the improved alternative positive displacement pump (1), the cylinder wall (4) comprises a piston sleeve (14) that is located on the inner side of the cylinder wall (4) and that extends over essentially the entire length of the pump cylinder (2) to the cylinder bottom (5). The improved alternative positive displacement pump (1) is further characterized in that, the main portion (13) of the pressure channel (12) is located in the cylinder wall (4) comprising the piston sleeve (14), which is thus preventing the pump piston (7) from touching or compromising the pressure sensor (10) or an inner surface (30) of the cylinder wall (4) when moving past the position of the pressure sensor (10). Also disclosed are a liquid handling robot that comprises a single or multiple arrangement of the positive displacement pump (1) and liquid handling workstation that comprises such a liquid handling robot.
