A new algorithm for calculating efficiency calibration has been implemented. It is based on orthonormal polynomial approximation and is capable of dealing with polynomials of degree up to 12 and to handle up to 20 experimental points. Additional utilities have been provided to control the calibration procedure including restriction of the maximal polynomial degree, applying corrections for coincidence summing, managing experimental data set (rejecting/restoring data from calculation) and graphical representation of the resulting curve and so on.