Mini Wind Tunnel including power connection cable: Draw up your own ISO calibration certificates! The Testo Mini Wind Tunnel can be used for regular checks on velocity probes and measuring instruments in your company. 3 speed levels can be set: 2.5/5/10 m/s. These readings are traceable to the PTB standard.Accuracy of wind tunnel is ± 1% of reading (at least 0.1 m/s) plus calibration uncertainty of the respective reference instrument's certificate.