generator guide bearing indicate a shaft deflection of 0.006 inch at 30º from No. 1 rotor arm. The 0.006 inch is the magnitude of vibration amplitude and the 30º counterclockwise is the location (direction). Using a scale (such as one-fourth inch equals 0.001 inch), draw the deflection as a vector. The 0.006 inch at 30º has been scaled as vector OA. Point O is the tail of the vector and point A is the head. Note that the arrowhead always points in the direction that the vector acts, in this case away from point O and towards A at an angle of 30º from the reference line. Thus, this vector can be represented by the notation OA and is not the same as AO.
6. Vector Addition
A vector can be added to another vector (original) by using graphical techniques. Draw the vector to be added using the head of the original vector as the starting point. A vector drawn from the tail of the original vector to the head of the added vector is the graphical sum (resultant) of the two vectors.
6.1 -Example 2: A vector OB having a magnitude of 0.005 inch and a direction of 150º is added to vector OA in figure 4.
4