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Thanks a lot Ed

Hey, Do you guys have any ideas about what kinda valve setup i should use for such a system where i use like 100ml of the refrigerant liquid (under pressure 700 kPa to keep it in liquid form) and make it flow across a short length of pipe (like 5cm max) with these plates inside. How would i...

@IRstuff Thank you. Yeah i sort of grasped what you were saying between those two posts. I really appreciate the help.

@IRstuff Thanks a lot IRstuff, i think that is a really good idea. I'll simulate using several plates and calculate the cell constant. I think i can reduce the internal diameter of the pipe and the volume now with this. @EdStainless I guess i'll simulate different designs including ones with...

@IRstuff Hi, sorry i haven't read the rules about posting in these forums. This post is a continuation from the previous ones, the last one was mainly concerned about how to calculate the cell constant for a ring design cell and how to construct a ring design cell. Now that i've done the...

@rothers we haven't done any tests yet, i'm still trying to design the device to do the tests. We'll test how the flow rate affects the results once it's built. The reason for this experiment is because 134a is used as an inhaler propellant and we're trying to understand how the resistivity...

Hi, I'm designing a cell to measure the electrical resistivity of a dielectric liquid during flow. I performed simulations and found that if i use a design with two electrode rings within an insulating pipe, it would require relatively large dimensions and thus a large volume if i want the cell...

Thanks a lot guys. You've given me so many good ideas i haven't even thought of. I'll do the simulation on comsol to get an equation for the cell constant and then decide whether this plate/screen design is better or the ring one. [peace]

@EdStainless I don't understand what you mean by plates, how does it look like exactly with a plate configuration? Also, I don't quite understand what you mean by this statement: Surely, a high charge density would be good to get a good current signal for dielectric liquids.

@IRstuff That's actually a good idea, thank you. If i did that, would I then just add all the cell constant values for all the chunks to get the overall value?

@IRstuff i understand that but that would require further adjustment of the design of the cell if the constant was found to be too high. I thought it'd be better to try to approximate it numerically and base the design on this approximation before constructing the cell, thereby saving time.

@waross Hey waross, Can you please explain what you mean by a 'screen' in this context and how that would give me parallel electrodes. I think you're right about this statement, i might need to solve it numerically via FEA instead using COMSOL: The problem with calibrating it is that it...

@thatguy1988 there have been 3 academic studies trying to determine its conductivity but the results they've got doesn't correspond to the behavior of 134a observed in industry. They think the academic studies are at least 4 orders of magnitude off. So they sponsored me to get better results...

@IRstuff Does that mean the area for the cell constant is calculated from the surface area of the anode in contact with the liquid while the geometry of the cathode does not matter? Thank a lot for the link btw, that was really helpful.

@waross Thanks for the reply waross. I really like your nipple idea. I was wondering what you meant by the quote above. This project is to understand the resistivity of dielectric propellants used in pharmaceutical inhalers when flowing within the valve stem of inhalers. We're not interested...

Hi, I need to design a flow-through cell to measure the electrical resistivity of pressurized dielectric liquids when flowing across a tube. The main liquid I want to test is 134a which is thought to have a resistivity of around 10^12 ohm-m (in a static state). I want to design the cell so that...

yeah my supervisor just told me the same thing about not using nitrogen, so i'll just be using 134a like you guys said. Thanks for the detailed process explanation @TiCl4. To answer your questions about purity and contaminants @IRstuff, the first container containing the 134a is too large to...

Thank you all so much. You guys are the best!! [thanks]

@Compositepro Thanks a lot for clearing that up. Sorry, didn't understand what the term meant from your previous posts. @georgeverghese Yeah i agree, will probably adopt that approach. @chicopee How do you propose to reduce the rate of discharge from the top valve? I've got two ball valves...

Thank you Latexman for the explanation. Anyone know what "liquid locking" means in this context as Compositepro was referring to in his comment above?