We have an aerodynamic balance in the lab specifically designed for the Lund wind tunnel. The balance measures lift, drag and pitch moment at a resolution of 0.005 N.
The forces are measured by three Kistler 9207 quartz force sensors, to measure drag, lift and pitch moment. Each sensor is connected to a Kistler 5037B3 three channel amplifier which is fed with 15 V from an Instek GPS-4303 DC power supply. The amplifier provides a -10 to 10 V force-relative output. The maximum range of force on each sensor is ±5 N. The amplifier is connected to an Advantech PCI-1710 PC Lab-card in a stand-alone personal computer. The input values are read and interpreted by custom built programs created in Matlab.
The balance consists of a metric table that is directly mounted on the force transducers. On the metric table a sting is mounted with a holder of models for measurement at its upper end. The holder allows different angles of attack to be investigated with an easy adjustment.