Remember what “curiosity” did to the cat…… 
… … 
More specifically, Dale and the brothers R decided I needed one, so they made it happen. If I understand correctly, it’s a brand new lumen tube and meter, full of diffusion sheets, calibrated with maukka lights, which should read out lumen numbers directly on the meter with no multiplier.
Of course, things may settle and shift a bit during shipping, so I’ll most likely recalibrate it myself to be sure. I needed to get some calibration reference lights anyway… so both tube and lights are on the way.
It’s a pretty huge upgrade from my current gear.
Maukka I was wondering. Do you have to recalibrate your sphere each time you use it with that “Lisun’s SLS-10W standard light source”. The reason I ask is some how I have found my 3” lumen tube way out of calibration again and I am not sure why. Everything is in the exact same place it has always been. The tempreture in my shop is up a little right now, but for most every test I do I put the lights and batteries in the house for a day before testing. I understand that absorbtion has to be calibrated for, but I’m even getting a different set of numbers on the same lights (such as the calibration S2+).
Did you try changing the batteries in your meter?
I always calibrate befoore taking measurements. Not with Lisun bulb but with three calibration lights to make sure everything is in order. There is usually some variation (a percent or two maybe) between sessions but as long as the correction factor between the lights doesn’t differ more than half a percent, everything is go. So there hasn’t been any lomg term drift for me and I also use an S2+ as one of the cal lights.
Dust is an issue I have, I have to clean my sphere every week or so to keep readings the same.
I have a SWM D40A (I measure the highest regulated setting) that I check my sphere with, and it reads between 10.95 and 10.85 (before multiplier, it is around 550 djozz-lumen) for years on end now. So it should be possible to stay consistent with home-made light measuring contraptions.
I do remove dust and grit inside the sphere every now and then with a vacuum cleaner, although some visible dust does not alter readings significantly.
Maukka… that set-up is DOPE!
lol what do you do for work? I’m very curious what professions utilize integrating spheres and the rest of your equipment.
I also one day want to build a lumen tube… maybe a sphere… lol I’m pretty ambitious but those both being a long time away I just wanted to say it’s very cool you taking the time to provide proper calibration equipment to the forum, 
He spent thousands of dollars for this equipment, not as part of his job, but just as a hobby. Cool, huh?
ARRRRRRRRRRRR!!! I didn’t catch that until just now…… 5.XX volts in the battery left. 
The readings were not only off they were scattered. They were all high, but not even by the same percentage. That pretty much took care of it. Now to go back and make updates all over the internet.
<3
Hey guys, am I calibrating my sphere based on the MID mode from (low,mid,high) on the driver?
Yeah, Mid.
Thx, was sanding down my sphere and wanted to make sure before I taken too much material off.
I use the BLF348 for the low calibration and the mid mode of the S2+ for the mid range calibration but honestly if the mid mode on the S2+ is good the 348 has always matched up as well.
This gives me a chuckle! My first measuring space was the small bathroom in the house and now, and you may have seen it, but I have an integrating 68 quart Coleman cooler. So, I call them 'Coleman Lumens'.
TK, Absorbing yours and others comments about determining OTF output with a DMM and improving my technique on that front, I've realized that OTF lumens are the real test... and has saved me $40.00 for a new clamp meter. This discussion on throwier v's flooder lights really helps me, going forward, on how to calibrate the readings (so far, 25 lights & combinations) with my Budget Lumen Measuring Rig.
Maukka, Your work is very much appreciated. Thank you!
Hi Maukka,
Are you still selling calibrated lights? I am from the Philiipines and I want to use your calibrated lights for my lumentube.
Yes, I’ll send you a message.
Thank you very much!
Hi Maukka!
I would like to buy a light for my 150mm tube built by ZozzV6 (he used your lights set to set the filters)
I think one light with 2 known steps should be enough to double check the tube now and then?