My custom discs for Convoy S21D and Wurkkos TS30S.
I cut it tight such that now no light could escape and the flashlight’s position on the lumen tube does not vary from one measure to another (one less variable).
It is tight enough such that the light actually could free-stand on the lumen tube and allows me to do runtime graph. And finger crossed the heat doesn’t burn my cardboard. 
Very nice job, looks great!
In case the light meter breaks, I bought a second one from Aliexpress https://www.aliexpress.us/item/2251832728458307.html?spm=a2g0o.order_list.order_list_main.11.20181802culLBy&gatewayAdapt=glo2usa&\_randl_shipto=US.
The item came promptly, but note it does NOT have any imprinted brand name or model number . Not too surprising for Aliexpress commerce I guess? The packaging looks identical otherwise.
To determine correction factor between the new meter and the original calibrated one, I did some comparison using flashlights with a wide range of outputs. Turns out to be around 7%.
Convoy S21D with 60° bead TIR: new meter reads ~7.3% less
Convoy S21D with 10° clear TIR: new meter reads ~8% less
Wurkkos TS30S: new meter reads ~6.7% less
BTW outputs for floody versus throwy lens on same flashlight like the Convoy S21D above are very close, another good sign.
Extremely happy I bought this. The numbers come out consistently similar to reviewers’ numbers, I guess especially since some reviewers actually use the same Texas Ace Lumen Tube (grin). It makes the hobby a lot more fun.
Yep, you point out exactly why I build each tube as a complete unit with everything installed. The smallest changes can effect the readings by surprisingly large amounts.
This is why TAs tubes are such a good deal. When I built my own version, it took literally months of fussing to get close to having the lux meter read out in Lumens.
I had pages and pages of various combos of tubes and diffusion baffles charted. When I finally got close, I’m sure Angles started singing in the distance.
Something as trivial as moving a diffusion disk 1mm in the stack or not connecting the pipes in exactly the same orientation makes a difference.
All the Best,
Jeff
Been there, did that lol. Took me over a year to dial in this setup and even then final calibration was not possible until I got maukkas lights.
You are also spot on, everything has to be exact in order for the readings to match, this is why I have to build/take it apart a dozen times or so just to get things close, then I glue everything in place before final calibration so I don’t have to worry about anything changing later once I dial in the calibration.
I did test various metal tapes. There were a few lumens difference in the brands when I used them as tube lining.
If you are concerned about matching TAs tape on newly made disks, make a similar test disk and see how much a difference it makes.
All the Best,
Jeff
Yeah, there will be some differences in the tapes, as long as the surface finish is close the readings should be close as well. You are correct, make your own disk the same size as one of mine and you know for sure.
That’s a good idea thanks. I will check but I don’t think it’s going to be a large difference as the reflection look very similar between the 2 tapes.
Still selling these?
Would love to buy one. I know the thread is years old but towards the end it looked like you had some left.
Yes, still got some! PM incoming.
I cannot recommend the TA lumen tube highly enough. Extremely simple to use and informative, making the hobby SO much more fun. Outputs follow “pro” reviewers’ numbers closely; I guess partly because some reviewers use it to measure also 
.
Agreed. And if you do your part holding the light properly in the centering ring, you will get very consistent results. I’ve been debating investing in a 3d printer. If I do, one of the first things I’ll make is printed centering rings to replace the custom cardboard ones I’ve been using for certain lights.
Hey Texas Ace, I would love to buy a 4.5 inch lumen tube from you. Or if you don’t have any of the 4.5 inches available a 3.5 inches one. Please let me know how to proceed
PM on the way
Hi Texas Ace,
i am interested in the 4,5 inches lumen tube.
PM inbound.
Also I can still make more tubes for anyone else interested, just making them to order generally now so it might take a week or so.
Is there a luxmeter other than the HS1010A that has the ability to record data and connect to the computer?
Currently I am doing my run time charts with a Benetech GM 1020 via Ceiling Bounce.
The sensor from the Benetech is smaller and therefore does not close flush.
So I would need a luxmeter that has the same sensor or size as the HS1010A.
Then I could make my graphs comfortably with the tube.
Of course, the lumen values with another luxmeter can deviate, but that is not bad for me.