I wonder if someone here with suitable test equipment could run a graph on a chemical glowstick, the ordinary 12 hour kind, not a special fancy one. I’m basically hoping for a rough estimate of the lumen output and its decay over time. I did a bit of web search and got drastically varying numbers. I guess I could make an eyeball estimate, but would want to use a reflector of some kind for the ceiling bounce.
Does anyone know if reflectors like the below are still being made? Of course I can DIY one if necessary. Web search didn’t find anything quickly, but it’s difficult to keep the results relevant.
https://www.worthpoint.com/worthopedia/nos-vintage-glow-stick-lantern-1960s-4706797024
I’m quite dubious of chemical light in this day and age, but they come up in discussions sometimes, so I’m interested in a concrete comparison against flashlights. Thanks!
Added: I’m happy to reimburse the cost of a few glowsticks if you’re up for running this test. Or it’s possible that I could order some and have them sent to you (Home Despot free delivery). PM if you want this.
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Unfortunately you are going to be massively disappointed.
There is going to be a massive variation of runtime, light output and reliability.
The things that will cause problems:
- Quality of manufacture - The runtime, light output and reliability will vary wildly depending on the manufacture and country.
- Size and shape of the stick - There is about 5 common shapes & sizes available that will affect the light output and duration
- Age (from date of manufacture) - Glow sticks degrade over time causing shorter run times/light output
- Packaging - Light and air intrusion can degrade the chemicals causing shorter run times/light output
- Temperature - Glow sticks stored in higher temps will degrade faster and will accelerate the chemical reaction causing shorter run times, colder temps will impede the reaction greatly reducing the light output.
- Storage - How they are stored is going to affect how reliable they are (rough handling can crack the glass vial &/or cause the stick to leak)
- Colour - Each of the different colour variations will have different light outputs.
- Stated runtime - Sticks commonly come in 4/6/12 hour versions (other duration available) shorter run times will be brighter but the longer runtime sticks will be less bright.
So to do tests you would be needing to test thousands of glow sticks at minimum to get anything close to reliable numbers.
That looks like AI output and no there’s no need to test thousands. Testing just one that acted fairly typical would be good enough to get an indication. Testing a handful would show if there’s much variation. Folklore has always been n=30 is usually good enough to observe the normal distribution, though that’s not so reliable really.
https://statswithcats.net/2010/07/11/30-samples-standard-suggestion-or-superstition/
Gee thanks for calling me an AI.
But nope it’s just things that I noticed (checks calendar) a long while back when I was looking at getting a bunch for my emergency kit.
I decided against buying them as they are an order of magnitude more fragile than an LED light, no guarantee that they will work when you need them and a ~4 years of shelf life compared to ~10 years for lithium batteries.
Modern LED lights can offer days and even months of runtime on a battery set, multiple light output levels and when paired with a lantern cap accessory or a cone of printer paper provides the same functionality as a glow stick while being far more versatile.
Plus combining several sets of rechargeable batteries, solar panels and charger you have consistent lighting for at home and having the option of keeping lithium batteries in your evac kit.
The merits of lightsticks versus LED’s weren’t part of my question. I just wanted a measurement, not purchasing advice. The idea that a single measurement is uninformative and that I really need thousands of measurements is ridiculous. It seemed like something an AI would say, but ok I guess a human could say it carelessly. If I thought a single measurement was suspect, I’d go for maybe 3 measurements. People infer all the time from way less than thousands of observations.
As for fragility, one suggested way to use a light stick is to put it at the end of a few feet of cord and swing it around in a circle, for more visibility from a distance. Most people won’t want to do that with LED lights.
