The Dynamics Cart and Track System with Motion Encoder (DTS-EC) can show a drift in the zero position of the cart when connected to a LabQuest when powered by certain AC adapters. This can be seen by leaving the cart stationary, and monitoring the position over several minutes. The reading can increase by several meters in five minutes. The original LabQuest can show the drift at a much higher rate, approaching a meter in a minute.

The problem is resolved by disconnecting the LabQuest from the power supply, or by connecting the LabQuest to a computer by USB. The former removes, and the latter mitigates, a source of noise from certain power adapters.

Not all LabQuest power adapters create this noise problem. For most physics experiment lasting only a few seconds, the drift is not noticeable.