National Physical Laboratory of India is realized by using an absolute radiometer. For practical work, a group of tungsten incandescent lamps are used. The level of uncertainty is ± 1.3 × 10. Experimental work has been initiated to realize mole, the SI unit for amount of substance The NPL does not maintain standards of measurements for ionizing radiations. This is the responsibility of the Homi Bhabha Atomic Research Centre, Mumbai. The standards maintained at NPL are periodically compared with standards maintained at other National Metrological Institutes in the world as well as the BIPM in Paris. This exercise ensures that Indian national standards are equivalent
Intensity (physics) Intensity (physics) In physics, intensity is the power transferred per unit area, where the area is measured on the plane perpendicular to the direction of propagation of the energy. In the SI system, it has units watts per square metre (W/m). It is used most frequently with waves (e.g. sound or light), in which case the "average" power transfer over one period of the wave is used. "Intensity" can be applied to other circumstances where energy is transferred. For example, one could calculate the intensity of the kinetic energy carried by drops of water from a garden sprinkler. The word