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PMS5003S option for the 3d printing crowd

Hardware extensions
#1

tl;dr;
People with 3d printers care about formaldehyde levels. PMS5003S adds formaldehyde level measurements for about $6-8 extra over PMS5003 and I’d love to have a kit with it included available as an option.

Long version:

ABS and, to the lesser extent, PLA, the two most popular 3d printing filament materials as well as many (most?) 3d printing resins emit not just your regular toxicity mixture of VOCs and fine particles, but specifically not insignificant amount of formaldehyde.

The amount of formaldehyde is a function of print temperature/UV exposure to a greater extent than many other VOCs, so having a separate measurement for formaldehyde specifically would be very useful for both health reason and also to have a warning you are pushing your printing material too far out of spec.

I suspect many people in 3d printing space would love to buy a kit - it’s not just me.

1 Like
#2

I’m also a 3d printer, although I currently only do PLA, I hope to try ABS in the future now that I have an all metal hot end. I just hadn’t looked up to see what specifically ABS emits that I wouldn’t want to breath to see if there was a sensor for it

#3

The TVOC sensor SGP41 that we offer for the kits can detect formaldehyde as part of the total with the other organic components.

#4

I’m aware, but a separate reading of formaldehyde levels is actually still useful enough to justify the additional cost of PMS5003S in my opinion, let me explain:

  • formaldehyde amount as a percentage of VOCs emitted spikes when printing material is pushed out of spec. This can be incorrect print settings, failing thermocouple, printer overcompensating at print speed changes, etc. Having a formaldehyde level is useful feedback if you, the software or printer doing something wrong and making it worse than it could have been.

  • some filaments and resins claim to be formaldehyde free and as much as I’d like to use those I don’t trust the marketing

  • it’s entirely possible many printing materials register as emitting moderate amounts of VOCs which in reality are anything but moderate amounts of formaldehyde with relatively low mount of other VOCs. Good examples would be some of ABS and Nylon filaments, but which ones we can’t tell, since resins and filaments are made of proprietary blends.

#5

As per spec sheet of the PMS5003S, it looks more like a TVOC sensor.

“Some other gas except formaldehyde such as alcohols ,benzene,xylene,cabon monoxide,hydrogen sulfide,can affect the sensor.” (Page 11)

#6

I’ve checked several sensors just now and it seems that some cross sensitivity is a common theme.

edit: I’ve contacted Plantower requesting cross-sensitivity data - I’m hoping it’s going to be about as good as Sensirion SFA30 - if it is it would still be useful for the purpose stated above.

#7

OK, I got a reply from Plantower and it’s not good news for my idea: they don’t have data about cross sensitivity to share and in the same email they recommend I use a dedicated formaldehyde sensor, which means they are not too confident about PMS5003S performance themselves.

I will do some evaluation myself: I managed to get PMS5003S for just $1 over regular PMS5003, so $10 for a dedicated formaldehyde sensor is in the budget. It’s going to be interesting to compare the 3 data sources (including TVOC sensor).

#8

Which formaldehyde sensor do you plan to use?

#9

I haven’t decided yet, but Dart WZ-S is the top contender right now.

#10

I’ve been testing the PMS5003ST compared to the SGP41. The SGP41 sensor has a “VOC Index” which normalizes to 100, so it’s really only good for relative measurements. The PMS5003ST on the other hand seems to give an absolute value.

Here is my living room comparing the two sensors, PMS5003ST on top:

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And here is my office. I painted this about 8 months ago and I can still smell the paint off-gassing. This can be seen in the much higher PMS5003ST measurement. The periods where it goes to zero is when I opened the window.

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Interestingly, my PMS5003ST sensors read higher values for PM2.5 than a PMS5003 sensor right next to it. This is consistent between different PMS5003ST and PMS5003 sensors.

My takeaway is that the PMS5003ST is more useful for long-term pollutants and is good to give an idea of the overall health of the environment. The SGP41 is more sensitive and can be used to indicate when something has changed to trigger some action.

Here is the code I am using:

#11

Following up on this topic as I now have the ability to print ABS. I have the SGP41 installed and so far haven’t noticed a particular spike when printing ABS and that is before my Nevermore filter.

The Index value of SGP41 is hard to use, since it is all relative as mentioned, but at least the graph comparing the PMS5003ST to the SGP41 shows similar rise and fall.

I think I may look at a PMS5003ST as well for some actual numbers to use.

Any other sensors that may be applicable to 3D Printing in general, or specific to ABS?