The Swarm satellites are equipped with two Langmuir probes to study the plasma environment around Earth. One probe is coated in Titanium nitride and the other in gold, providing a unique opportunity to study surface effects for different coatings. At their altitudes there are neutral particles that may contaminate the probes which adds an uncertainty in their measurements in the form of a time delay. The time delay is most evident by a shift in the current-voltage curve when the upsweep is compared to the downsweep. Using a simple model to fit a simulated current-voltage curve to the sampled curve, it is found that two of the three satellites have a time delay that ranges between 0.627 ms and 1.34 ms. In addition to contamination, there may be additional sources of measurement error that stem from the local environment that are not studied as they are not linked to contamination.