On Tue, 24 Oct 2017 20:28:21 +0100, Andy Burns wrote:

Johnny B Good wrote:

Dave Plowman wrote:

Simply state the light output in a standard way.

They already do, using a Lumens output figure (typically 806 or 810
Lumens for the classic A bulb American 60W GLS lamp).

I often get asked to replace one or more blown lamps when I visit my
parents (they have 5 + 3 fittings in lounge and dining room) I noticed
that the boxes for the 60W incandescent lamps this time *were* marked
clearly in lumens.

JOOI, can you recall the lumens figure on those 60W lamps (assuming that
you're in the UK)? I'd expect a much lower figure than the 806/810 lumens
figure typical of a "60W" LED lamp for 240v 1000 hour rated GLS lamps.

According to wikipedia https://en.wikipedia.org/wiki/
Incandescent_light_bulb#Electrical_characteristics (sorry about the line
wrap) the lumens output figures for 120 and 230 volt 60W lamps are 850
and 730 respectively. However, I notice anomalous figures being shown for
the 25W lamps (transposed column data?) so I wouldn't assume any
accuracy, just 'Ball Park' figures.

Bear in mind that for a LED lamp to lay claim to being equivalent to a
60W 120v 750 hour rated incandescent lamp, the 806 lumens figure is at
the bottom end of the tolerance range for said 60W reference light source.

--
Johnny B Good