double BCAL_tdiff_res(double geometric_mean, int ilayer)
{
	double &x = geometric_mean;
	switch(ilayer){
		case 1:
			return 0.0187734+(2.76582/(pow(x,0.499703)-4.74858));
			break;
		case 2:
			return 0.0695365+(0.128973/(pow(x,0.12336)-1.50341));
			break;
		case 3:
			return 0.311245+(992.719/(pow(x,1.70212)+191.74));
			break;
		case 4:
			return 100.0;
			break;
		case 5:
		case 6:
		case 7:
		case 8:
		case 9:
		case 10:
			return 100.0;
	}

	return 1000.0;
}