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40W TUBELIGHTS
Only 1 Brand Found Close to Ideal Efficacy

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Insight — The Consumer Magazine of May-June 2005 has published the findings of its in-house comparative product testing laboratory on 13 brands of 40W tubelights.

Since March-April 2003, 10 samples of each brand have been kept switched ‘on’ — on a 24-hour cycle — briefly switching them ‘off’ at intervals, as specified by the Standards, to find out how long they last, how bright the light is, and how much the consumer can save by using them, both on money and energy. About 3000 hours of continuous testing is over and some of them are still burning.

Which is the Most Efficient?
The tubelight that gives the maximum light while consuming the least amount of power is the most efficient of them all. Higher efficacy means lower energy consumption and thus lower energy bills. The ideal efficacy of a 40W tubelight is 61.25. Though none of the brands met the ideal limit, among the conforming brands, Surya HBT showed the highest average at 60.04, and Anchor Classic showed the lowest at 56.22.

Tubelight Vs Bulb
Incidentally, three basic reasons why a consumer should switch from a bulb to a tubelight are : to save power, to get more light and for a longer life. At 230V the ideal efficacy of a 40W tubelight is 61.25 whereas that of a 40W bulb is only 10.37. A tubelight will last 2 to 3 times longer and give 6 times more lumen than a 40W bulb.

‘Best Buy’
We recommend Wipro, Surya HBT and New Cema Super as our Best Buys among the 40W tubelights.

Initial Lumen
Lumen is the measurement of light output and the IS specifies that for a 40W tubelight, whose rated lumen is 2450, the initial light output of an individual lamp should not be less than 2254 lumens. Surya HBT showed the highest average at 2422 lumens followed by Wipro at 2414 and New Cema Super at 2397.

This test required 15 samples of each brand. We found that all the 15 samples of each of the two brands, Powerlites and Bengal Lamps (CM/L - 8348989), failed to conform to the test requirements. These two brands were then dropped from all the other subsequent tests.

Beware of Fakes!
Our tests even unearthed fakes of well-known brands! We discovered that Powerlites and Bengal Lamps (CM/L-8348989) which failed to conform to the test for initial lumen, carried the same licence number. We couldn’t locate their address in the BIS list of licensees. So we wrote to the BIS authorities, who replied that, according to BIS records, licence number CM/L-8348989 does not belong to any of its licensees for tubelights. The BIS has also asked its officers to investigate the availability of spuriously marked ‘Bengal Lamps’ tubelights in Delhi, Haryana and UP and to take necessary action.

Lumen Maintenance (Lumen after 2000 hours)
The tubelights have to not only last long but also give good quality of light during the number of hours it lasts. According to the Standards, lumen ratio after 2000 hours to the initial lumen of an individual lamp shall not be less than 85 per cent. All brands conformed. The average lumen maintenance ranged from 94.27 in Osram to 87.15 in Bengal Lamps (CM/L - 8527181).

How Long Do They Last?
As per the IS, the tubelight should operate up to 2000 hours. We have been continuing the test of tubelights for 5000 hours as per the ‘scope’ of IS 2418 (Part 1):1977, (Amendment 3). Some brands are working even after 3000 hours. The 5000-hour test will take us about two and a half years more to complete.

Ballasts (Chokes)
As energy-efficient electronic chokes are now available in the market, we tested the tubelights’ ratings for the consumption of energy with electronic chokes. Energy consumption with electronic chokes was found to be much less than that of electromagnetic (copper and aluminium) chokes. The purchase cost of electronic chokes is a little higher than copper chokes, but can be recovered within 11 months (approx.) because the utilisation cost of electronic chokes is much less. (Low power consumption = less electricity bill). This test is not specified in IS 2418-1977.

Claims Vs Facts
We also analysed a few claims on the packaging vs. the facts. The Standards require the minimum initial lumen to be 2254. Philips Champion and Anchor Classic claimed 'Brighter Light' and 'Extra Light', respectively. Our result showed that they gave more than the requirement. But there were brands (Wipro, Surya, Cema) that did not make such claims and yet performed better.

As a policy, before publishing the results, we convey the test findings to all the manufacturers for their views and comments. They receive only the results of their own products. Excerpts:

Prestige Onida, the manufacturers of Bengal Lamps (CM/L 8527181) tubelights, said their “product is excellent in quality and has very good life and is able to render bright light...”

Insight : Standards specify the initial lumen to be 2254(min.). In Bengal Lamps (CM/L 8527181) it ranged from 2273 to 2430. Although it was lower than the lumen output of most other brands tested by us, the initial lumen of 15 samples was 2315. The results support their claim.

GE India Industrial (P) Ltd., the manufacturers of GE Standard tubelights, said that they use plain cut tubes and glass shells manufactured in their own company. Glass shells are produced by ribbon technology and the same glass is used for producing PCTs, so as to obtain uniform wall thickness and defect-free glass which leads to uniform white light.

Insight : Manufacturers adopt this technology. It has the advantage of uniform light and therefore the claim is substantiated.

Anchor Electronics & Electricals Pvt. Ltd., the manufacturers of Anchor Tubelights, said that in tubelight manufacturing process, fluorescent powder coating on shells is of various types. In our process, coating of shells is by aqua-based technology.

Insight : It is a common technology adopted by many manufacturers and cannot be called a claim.

This issue of Insight has all of these — one tubelight with two monograms, manufacturer’s volte-face when reported on the performance of the brand, etc. — and more.

Details of rating and ranking, the ‘Best Buys’ and excerpts of our correspondence with the manufacturers have been published in the May-June 2005 issue of INSIGHT — The Consumer Magazine.

Date : 21/07/2005
Place : Ahmedabad

Pritee Shah
Editor - INSIGHT

Annexures:
1. Brands tested, Standards
2. Test Results of 40W tubelights
3. Claims Vs Facts