In a monoenergetic ionic thermocurrent (ITC) band, the area S1 of the part of the band to the left of the peak (for T < TM) and the area S2 to the right of the peak (for T >TM) have a ratio a = S1/S2 that is related to the quantity x = E/kTM where E is the activation energy and TM is the temperature corresponding to the peak. In this paper the function a(x) is found and an approximating expression is formed with the method of computer fitting.