def convert_force(voltage):
    """
    Formula used to convert sensor data voltage reading into Newtons as per
    predetermined sensor calibration curve

    Calibration curve - Oct 24 2018
    grams   N       voltage
    0       0.000   298.7
    100     0.981   334.2
    300     2.943   405.9
    500     4.905   477.5
    800     7.848   585.1
    1000    9.810   656.5
    1200    11.77   728.5
    R^2 = 1
    y = 0.0274x - 8.175

    Calibration curve - Feb 19 2019
    grams   N       voltage
    0       0.000   305.4
    100     0.981   341.2
    300     2.943   413.0
    500     4.905   484.2
    800     7.848   592.6
    1000    9.810   664.6
    1200    11.77   735.6
    R^2 = 1
    y = 0.02733x - 8.3447
    Shift of approximately 0.17 N (17.3 g)
    """

    return round(0.02733 * int(voltage) - 8.3447, 6)