import sympy as sp

class Einheitenumrechnung:
    def __init__(self):
        pass

    def mas_to_rad(mas):
        umrechnungsfaktor = 1 / 1000 * 1 / 3600 * sp.pi / 180
        grad = mas * umrechnungsfaktor
        return grad

    def mm_to_m(mm):
        m = mm / 1000
        return m

    def ppb(ppb):
        ppb *= 10 ** (-9)
        return ppb