nThe ideal efficacy of a 36W tubelight, i.e. the value obtained by dividing the rated light output (2425 lumens) by the rated wattage (36W) is 67.36. In 36W tubelights, the average efficacy (lumen/wattage) of Bajaj was the highest at 67.57, followed by Osram at 66.86.

The average initial lumen of Bajaj was found to be the highest at 2496 followed by Osram at 2457. Anchor Slimline was found to be the lowest at 2262.

As per the Standard, the initial readings for the power consumed by 36W tubelights should not exceed 38.3W. All seven brands of 36W tubelights conformed to the requirements of initial wattage.

The use of an electromagnetic choke helps save a significant amount of energy. The initial purchase cost of an electronic choke is a little high but can be recovered within a year because the utilisation cost of an electronic choke is much less as there is less power consumption.

The energy cost per year of four tubelights consuming 40W and burning for seven hours a day and at an energy cost of Rs 4/kwh is Rs 1,635.20, while that of the same number 36W tubelights is Rs 1,471.68. Thus a consumer may save about Rs 163.52 a year in energy cost by replacing a 40W tubelight with a 36W one without compromising on the light output.

All the brands conformed to the requirement of Standard for initial lumen after 2,000 hours.

The total harmonic distortion (THD%) of electronic chokes Gelco (GC - 140) and Rocker (Sr. No. 10111) was found to be very high.