Transmission through a drift tube has been measured for different types of ions. Various ions were injected at the same rate at the start of the drift tube. Then, the transmitted currents were measured at the end of the drift tube. The results show that transmission depends linearly on the inverse of the drift time. Factors influencing the drift time, such as pressure, temperature, and electric field, were also investigated and shown to affect the transmission efficiency in a similar manner as the type of ion. A simple model based on kinetics of two parallel processes (loss or transmission) is proposed to explain the results. Since slow-moving ions are lost more often than fast-moving ones, the intensity of ion peaks decreases as drift time increases. This can be easily corrected by transforming the y-axis to y×x (i.e., intensity×drift time).