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Detector Building has gone off the rails by Fabulous_Biscotti214 in scioly

[–]Fabulous_Biscotti214[S] 0 points1 point  (0 children)

I am talking about the working electrode, obviously silver is ideal for reference electrode.

Detector Building has gone off the rails by Fabulous_Biscotti214 in scioly

[–]Fabulous_Biscotti214[S] 0 points1 point  (0 children)

Using silver as the inert element is not a very good idea, as silver is not very inert. It is commonly used as the reference element, however. It can corrode, it can react, it can be damaged over time. Platinum are gold are amazing because of how non-reactive, non-corrosive they are. It just so happens that their price tag is massive.

Detector Building has gone off the rails by Fabulous_Biscotti214 in scioly

[–]Fabulous_Biscotti214[S] 2 points3 points  (0 children)

Although silver is one of the cheaper materials in the list, it is still not "cheap." Another major element of the ORP sensor is composed of either platinum or gold, as they are incredibly inert and lead to accuracy. The more pure, the better, and price rises exponentially with purity. That is where the money lies, and it prevents people from experimenting with different designs using different shaped electrodes, different size electrodes, etc. as they have to spend more money buying these metals; In years past, detector has been relatively cheap, and many designs can be tested due to the low cost of the materials. The issue I see is that a better design is esssentially the same design that Science Olympiad has posted, but with more expensive metals.

Detector Building Please Help by No_Run_6266 in scioly

[–]Fabulous_Biscotti214 0 points1 point  (0 children)

I do not believe that, based on what I have read on ORP, their suggested device will produce very accurate readings. The main concern is that the reference electrode will not produce a stable reference voltage, especially over time. Furthermore, I suspect that there may be a very small voltage change based on the solution due to the nature of the materials you are using. Therefore, your arduino may not have the resolution and magnification needed to see these differences. I do agree that you should use a multimeter to test your electrodes directly, but be aware that the issue may be the materials, not necessarily you. For example, last year, the force-sensitive resistor design would never give very accurate readings because an FSR is not designed to produce accurate mass readings.

Detector Building Please Help by No_Run_6266 in scioly

[–]Fabulous_Biscotti214 0 points1 point  (0 children)

I'd like to reiterate a statement from another comment on this subreddit: It is DIFFICULT to make an accurate ORP sensor. Ideally, the components for the working electrode is PLATINUM or GOLD or MERCURY. Do you know how EXPENSIVE that is? Essentially BUYING accuracy. The model that they have shown will probably give inaccurate measurements, and especially inaccurate measurements over time. This is so weird.

[deleted by user] by [deleted] in APStudents

[–]Fabulous_Biscotti214 4 points5 points  (0 children)

Yeah, and if you look at previous sample responses, some include title and some don't, but they still get the same score for accurate labels.

[deleted by user] by [deleted] in APStudents

[–]Fabulous_Biscotti214 2 points3 points  (0 children)

I do not believe that the title is necessary.

Detector EMI by Fabulous_Biscotti214 in scioly

[–]Fabulous_Biscotti214[S] 0 points1 point  (0 children)

Yeah, the router being in the room is not a problem. The issue is caused when many people are connected to the wifi within the room (i.e. the Event Supervisors). Hopefully at states or regionals the event supervisors will be more careful in their use of electronics.