Luminous intensity is the concept for the concentration of light in a specific direction, radiated per second. The luminous intensity can be defined as: the luminous flux in a certain direction, radiated per unit of solid angle (steradian). [4]

A solid angle can best be described as a measure for a portion of space around a point bounded by the surface of a cone whose top (vertex) is at the point .
In general a light source will not radiate its luminous flux uniformly in all directions. If however, we imagine a sufficiently narrow cone, with its vertex at the light source (which is considered as a point), then the luminous flux contained in this cone will approximate a uniform distribution. The concentration of luminous flux within this narrow cone can now be defined as the luminous flux in this cone, divided by the opening of the cone, expressed in terms of the solid angle of the cone. The result is called the luminous intensity (I), measured in candelas (cd), in the direction of the center-line of the cone. [4]

Example of equipment to measure:

It is not possible to measure the luminous intensity.
In order to get the value of the luminous intensity you have to measure the illuminance and calculate it with the inverse square law.