Apparatus for testing pipetting needle linearity in an automated analyzer

An analyzer comprising:

• a) a horizontally disposed baseplate on which primary containers and secondary containers are disposed;
• b) a metering device for measuring a predetermined volume of a liquid;
• c) a pipetting needle for transferring a predetermined volume of liquid from a primary container to a secondary container, the pipetting needle being formed of an electrically conductive material and being connected by tubing to the metering device;
• d) a transport device for the controlled transport of the pipetting needle in three directions at right angles to one another, two of the transport directions extending horizontally and the third transport direction extending vertically;
• e) an electrically conductive reference body having a top edge and being positioned at a predetermined location with respect to the analyzer;
• and
• f) a control device for controlling the metering device and the transport device, the control device comprising:
• 1) means for guiding the tip of the pipetting needle around the the external periphery of the top edge of the reference body, the tip of the pipetting needle being guided at a specific distance from the top edge of the reference body, the distance being a measure of the acceptable curvature of the pipetting needle, and
• 2) an electrical circuit between the pipetting needle and the reference body for detecting an electrical contact between the tip of the pipetting needle and the reference body.