Aerosol/Aerodynamics Engineer: design a sampler/chamber for measuring CO₂ and PM (SEN6)

Drawings & Diagrams, Mechanical Engineering & Instrument Making — incorrectly specified categories?

200 USD

Client's review of cooperation with freelancer

Aerosol/Aerodynamics Engineer: design a sampler/chamber for measuring CO₂ and PM (SEN6)

200 USD

Maxim misled regarding his experience. He claimed to have practice in the field of gas/aerosol sampling and working with PM and CO2, but in fact, he did not demonstrate any real examples, technical solutions, or correct diagnostics of our design, let alone a working prototype. The responses were general and provided no practical benefit.

This is all because there is a clear impression that he used AI simply to generate both the "analysis" and the responses, and even reformulated our requests, effectively running the task through AI instead of doing real engineering work. This created a false sense of competence, but essentially the performer turned out to be unfit for this task, as he lacks relevant experience specifically in this area.

I do not recommend.

1.0

Yuriy Karnaukhov

18 January

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Essence of the Problem

We have a sample selection from the flue (after the electrofilter).
We designed and manufactured a metal probe/chamber (drawings are available), but the current design does NOT work at all:

CO₂ (ExplorIR) is NOT measured through the current design (readings are incorrect/practically 0).
PM (SEN66) is also NOT measured through the current design (almost 0).

That is, our existing probe/chamber “muffles” the sample or creates conditions where the sensors do not see the real composition of the air.

What We Did for Verification

To verify the principle, we conducted a “radical” test with improvised materials:
a regular plastic bottle as a chamber + the same tubes/pump.

And in this variant CO₂ immediately started to work stably and correctly, while PM also began to show meaningful values.

So the problem is almost certainly in the geometry/physics of our current metal design (sample loss, settling/sticking, condensate, incorrect flow, “dead” zones, etc.).

What We Have

Drawings of the current probe/chamber (will provide).
Photos/videos of the actual installation.
Actual installation: flue after the electrofilter.
Pump (around liters per minute), valve/sample collection cycles.
Sensors:
- CO₂: ExplorIR (NDIR)
- PM: Sensirion SEN66 (module with a fan). Ready to consider an alternative (more expensive, but reasonable, without x20).

Why the Task is Non-Trivial (What is Important to Consider)

Gas/particles can cool down along the way → condensate.
For PM (particles) it is critical: inertia, settling on walls, stickiness, electrostatics, geometry of turns/expansions.
For CO₂, important factors are: tightness, correct flow/exchange of volume, absence of “blind” zones/faulty suction.
A chamber/sample collector is needed that provides a representative sample and does not “kill” the sensor signals.

Task

A strong specialist is needed who:

Will figure out why our current design measures nothing (neither CO₂ nor PM).
Will propose and design a new structure (chamber/sample collector/flow geometry) that:
- provides normal exchange/flow of the sample,
- minimizes particle loss (PM),
- takes into account condensate/temperature/materials/statics,
- is suitable for industrial use.
If necessary, will advise on another PM sensor/approach (but without a cosmic budget).

Work Result

Diagram + explanation of the principle.
Drawings/3D (STEP/DXF) or detailed sketch with dimensions.
Recommendations on materials/components.
Test/validation plan (how to prove that the new design works).

Payment and Bonus

If after your modifications/design the tests show stable and adequate CO₂ and PM, we will double the bonus.

What to Send in Response

1–2 examples of similar tasks (aerosols/CFD/gas ducts/sample collection).
Briefly: what you will start the diagnostics with and what you can propose
What tools/approach you use (calculations/CFD/practical experience possibly simulations?).