Try using a union. Here's something you can get started from:
union U {
int i;
float f;
};
U temp;
temp.f = 439.09;
int i = temp.i;
Step through that and see what
i
equals. Then play with your values and see if things come together for you. If the sensor is not supplying the float value per standards, you will have to come up with a custom method.
Hope this helps!