Just to reiterate, I am attempting to measure air density. I don't need absolute values as they will be relative to the small sample of air we are sampling. The sampling frequency only needs to be once a second. We are using ionisation to create a signal to measure velocity. My question is: if...
We are developing a mass air flow sensor so we need air velocity and density. Could we use the pressure reading to help the calculation. We can also measure the charge density in an area where the air is almost static. Can you suggest any documents that would detail the pressure/permittivity...
I am greatly indebted to you dgonPhys.
This is precisely what I have been looking for.
You have got it spot on in every event.
All the research I have been doing resulted in overcomplication because the assumption is always that you should know all the basics already. The most instructive...
A is the closest. I didn't want to complicate matters by providing the actual wheel geometry as it is complex. By measuring the surface charge of the wheel we can see that the charge density and polarity varies significantly with the highest concentration of charge appearing at the blade edges...
OK - this is the situation. I came up with an idea for measuring rotational speed for a plastic impeller wheel. The idea is attractive because it is embedded and therefore causes no turbulance. I have been designing electronics since before the transistor, I am 66, but this level of theory is...
The electrodes are 6mm apart and 5mm sq.
The applied voltage is 200V fed via a 1M resistor.
The polymer rotates producing a 100mV sinewave output.
I would like to show parameters of: permittivity/charge density and capacitance.
It is intended as part of the technical review that will be...
Hi,
this simple principle is proving difficult to resolve.
We need a concise formula to describe the following:
An air dielectric is formed between two fixed electrodes.
When a charged polymer is passed between them the containment field is modulated.
We require an elegant formula to...
Thanks you for that, Bob.
It is not quite as you have assumed from my crude description: the capacitor is fixed and we utilise the charge congregated on the edges of the blades of a plastic impeller wheel to modulate the dielectric field. We were thinking perhaps of 'field displacement' ?
We have recently developed a motion sensor that introduces charge into an electric field. From the 200V (containment field) we derive a modulation of 100mV. Although the sensor has passed pre-production tests we are struggling to come up with a simple formula to describe the operation. Can...