Maybe you need to calibrate it? Use a light source with known wavelength (either lasers or gas discharge lamps) to calibrate the spectrometer. Keep in mind don't point lasers at the spectrometer directly, point it towards paper.

Took some Creatine and got some weightlifting in earlier in the day, then got some pizza from Dominos as a protein meal, followed by a protein shake. (Vanilla muscle milk protein shake is the best.) 8 out of 10 for the pizza, as usual... 9 out of 10 for the protein shake.
Also... off topic... I'm beginning to notice the high view count this topic has been getting... I know there are a lot more members on LG compared to way back in the day when I first joined in 2010, but... who's viewing this so much? Bots?

There were also gramophone lamps. http://www.douglas-self.com/MUSEUM/COMMS/oddgram/oddgram.htm#lampRead the whole page too if you want, and also just look at the whole Museum of Retrotech on his site. This Self person is cool.

Yeah, that is freaky. I wonder if bright emitter vacuum tubes were ever used for lighting as well as, well, doing the usual tube things; a big transmitter tube could probably light a large room.

@RRK
I am fairly certain (looked it up a while back, can't remember) that my solder does contain copper. And I can confirm that if it erodes at the rapid rate that is does now with copper added, I can only imagine that it would erode unusably fast without copper.

Aliexpress is not known for providing particularly good quality products…

The iron layer dissolves in the solder? Isn't that not supposed to happen, like the point of plating it in the first place? Or is some dissolution necessary for wetting?

Sure. Some of soldering tip material is lost continuously. Iron plating just slows this down considerably, that's the point. Still, tips are considered spare parts having a limited life.

Interestingly, today most of lead-free solders have circa 0.5% of copper added. Having this may slow bare copper tip dissolution in the solder, but no one in their sane mind uses bare copper tips in 2026 so it is hard to verify...

High impedance grounding is is not possible because it still allows to some voltage spikes to leak through heater - tip capacitance. Modern general purpose components like microcontroller ports or 74HC logic are in practice quite impressively robust to abuse by mains leak currents and static electricity, but you'll get some components killed randomly with careless work, like small SOT23 MOSFETs having low gate capacitance.

 

For serious work, industry rules call for hard grounding everything involved. Hard grounding operator person is dangerous, so some current limiting resistor of circa 1 megohm is added.

In addition to mandatory grounding, GFCI may or may be not in use, not for actual components protection, but for stopping insulation deterioration problems *earlier* before they grow to full blown short circuits.  Downside is as always some nuisance tripping happens due to interference.

 

@Ash
Thanks for all that info! Yeah I don't think a mains transformer is crammed into the handle of my iron, and I think I have tested it's continuity to ground before and concluded that it is directly connected. I haven't worked with those extra low voltage sensitive components before, but if I do I will definitely be careful and do research.

I wonder if it would be possible for manufacturers to integrate a GFCI-like device into the iron to be able to omit the transformer and still have high impedance grounding. Maybe that would be more expensive than just having a transformer, who knows.