Hello
I'm not quite sure on where im to post for a bit of help - But while im here
Hi my name is mark and i looking for abit of help. Ok i explain my issue, A local tip is releasing H2S gases and its making the residents sick, The local papers are now on board as well as the Environment agency and our MP - who are taking readings of these said gases. " can you see were i am going with this".
Ok i would like to make a unit that does similar thing, I know what i want to do and i have bought majority of the items, but i have no clue on how to make it work. I have the sensors, wifi + bluetooth module, radio module etc etc. So i wondering if theres a company that would build me the unit if i posted the items out to them & pay for any missed items and the build. Im also pretty sure many other people would follow and also be wanting the same.
Im sorry my very first post is asking for help
Cheers Mark.
try a local hacker-space? school?
List the names (part number) of what you've got. Maybe someone has the googlefu to get you something up and running
If you want a bespoke sensor developing - and it sounds like you do - then I'm afraid you have it completely backwards.
The way to go would be:
- decide what you need, in terms of inputs (presumably H2S concentraion), outputs, features and performance requirements (accuracy, reliability, calibration and traceability etc)
- then approach a design engineer with your functional requirements
- then, once the design is complete, and if you want to build the unit yourself, buy the components that were specified by the design engineer.
Right now, there are two things I can absolutely guarantee:
1) It'll be cheaper to buy a complete commercial unit off the shelf than have an engineer build you a bespoke one.
2) It'll be cheaper to hire an engineer to design a complete sensor and to buy a new set of parts, than to buy a set of parts and then hire an engineer to design a sensor which is constrained to use the specific parts you've already chosen.
[Dis]claimer: I design sensors for a living.
About the H2S sensor itself:
$20 each:
https://www.spec-sensors.com/product/h2s-sensor/A complete solution with data logging under $100 (no wifi, though):
https://www.pksafety.com/msa-altair-h2s-single-gas-monitor.htmlSo, it seems that it may be possible to design something inexpensive using a cheap sensor and with a readily available microcontroller module (like those cheap ESP8266 or ESP32 modules with Wifi and Bluetooth) plus some buttons, OLED and rechargeable battery. Of course the development will take some serious time and effort, which typically equal to $ $ $ $. For the required precision I would purchase a calibrated instruments in order to be able to validate the measurements of the cheap sensor modules.
In addition to what AndyC_772 wrote:
If you want the readings to have any legal meaning (and I suppose that is the goal) then you will need to buy a commercial H2S sensor unit with traceable calibration. Readings from a self build sensor unit without calibration will have no meaning in court and/or to any legislative body.
You can often save money over buying a commercial unit by building yourself, but if you're going to pay someone else to build it then you'll be better off buying an off the shelf solution when one exists.
If you want the readings to have any legal meaning (and I suppose that is the goal) then you will need to buy a commercial H2S sensor unit with traceable calibration. Readings from a self build sensor unit without calibration will have no meaning in court and/or to any legislative body.
This ^ ^ ^ ^ ^
Without proper calibration behind it, you'll be hard pressed to show in court when the emissions were
comparatively better or worse on a given day. I don't see you having much luck using such a home-brew device in a successful prosecution.
I would guess you'd have more luck if the whole community, or as many as possible, send air samples to the Environment Agency's analytic lab(s) demanding that they test it for H2S. If enough people send enough samples they will have a real job just losing them behind a filing cabinet. Just a thought, as air samples are easier to take than analyse.
Hi my name is mark and i looking for abit of help. Ok i explain my issue, A local tip is releasing H2S gases and its making the residents sick
Environmental pollution sucks. But H
2S is very smelly. So much so that the human nose will be offended long before there is any health issue. So the first and most obvious thing to do would be to keep a journal noting times and dates when the smell is evident, and maybe also noting the weather conditions, wind direction, and so on. Do this over a month or two and you will have a very valuable record to show to public officials and other relevant organizations or government bodies.
In regards to everyone claiming calibration as an issue for court - they're absolutely right.
For instance - if you're stopped for speeding, if the device wasn't calibrated right before use, then the citation can be dismissed on grounds the device wasn't properly calibrated - this will work for most cases as most speed detection units manuals state they need to be calibrated before each use... On a side note - the posted speed limit isn't the legal speed limit - you can ask for a traffic survey to be done which will tell you the legal speed limit ( which is the average speed of the whole for the area during the same weather / light conditions - obviously people will be going above the limit, and below - but the average is the legal speed limit and there is a legal precedent for this )
Now - you could build your own unit to get a general idea, and you can log that data... However, if you want that unit to contain any weight in court you'll need to hire an expert witness to corroborate your findings and someone to verify that your sensor is within spec.. Otherwise the defense will have the case dismissed because 'homemade' electronics aren't 'scientific' enough to prove any wrongdoing... If you're unlucky the case will be dismissed with prejudice meaning it can never be tried again... They will ask for that if the opening is weak or the evidence is that poor - although a judge will likely NOT do that especially if you argue people are getting sick - and you can then ask for a continuation in order to hire an expert witness, and to have additional testing done...
However, it's best to have all ducks in a row before you take it to trial, otherwise you'll end up making the judge feel like their time is being wasted.
Now, depending how large whoever it is you're going up against - for every expert witness you hire, they'll likely have 1 to 10 saying otherwise... So make sure whoever you hire as an expert witness, calibrator, or company to perform the scans are legitimate, top of their field, honest with integrity so they can't be dismissed on the stand... So it can't be anyone that's worked for the company as your primary - they can be a witness but they can't be THE witness because if they were fired, or whatever.. the defense will argue motive to falsify testimony and it'll make it look like the person isn't credible at all....
Be meticulous about gathering information - make sure any witness / expert witness who speaks, is subpoenaed, or is hired doesn't have anything which can kill their credibility otherwise you're done...
Hello
I'm not quite sure on where im to post for a bit of help - But while im here
Hi my name is mark and i looking for abit of help. Ok i explain my issue, A local tip is releasing H2S gases and its making the residents sick, The local papers are now on board as well as the Environment agency and our MP - who are taking readings of these said gases. " can you see were i am going with this".
Ok i would like to make a unit that does similar thing, I know what i want to do and i have bought majority of the items, but i have no clue on how to make it work. I have the sensors, wifi + bluetooth module, radio module etc etc. So i wondering if theres a company that would build me the unit if i posted the items out to them & pay for any missed items and the build. Im also pretty sure many other people would follow and also be wanting the same.
Im sorry my very first post is asking for help
Cheers Mark.
Hi Mark, It's fine to ask for help and it sounds a fun project but why do you not trust the Environment Agency?
They have all the equipment (complete with UKAS traceable calibrations) to do this for you and will do it without prejudice to create an honest and accurate report which can be used in a court of law if necessary to compel the operators to clean up their act.
Any sensor you create will need some kind of calibration to be accurate and calibrating a gas analysis device to known standards is not a trivial task.
Sure, build the project, try and learn for yourself, it's fun, but be aware it will be a waste of time and money if it comes to litigation, it could well get the case thrown out if you attempt to rely on any readings you produce unless you can provide a traceable calibration and statement of inaccuracies/probability of uncertainties.
a good friend of mine runs their own business doing environmental monitoring, with all the right kit and it's all certified etc.
if you want i can see if they are able to help?
The OP has posted this 3 months ago, and has never followed up — not a single further post. I think we can safely forget about their enquiry.
They did, you're right, dead subject.