Hi,
I need an answer as soon as possible because my VIVA is just around the corner (in June) and I haven’t really done any experiments yet with my spinning cylinder in the wind tunnel.


Everytime I switch on the power so that my Kyowa pressure transducer (that is in the middle of the cylinder) gives readings, there is a value that is not equal to zero (it always shows a value of about -0.000426 strain rate) eventhough the cylinder is not rotated yet and the wind tunnel is not switched on. Can anyone tell me how do I compensate for this so that the reading w/o stress could be zero?

Another thing, I heard about this offset nulling circuit. Can it be applied to my case? And this op amp, is it the same thing as the Kyowa pressure transducer that I am having?

Thank for your quick answers folks.......

 

An operational amplifier is not a pressure transducer.
Look here:http://www.allaboutcircuits.com/vol_3/chpt_8/1.html

After you read that, name the operational amplifier you want to use and we will see about an offset compensator.

 

After reading the op amp characteristics (part 1) I guess op amp is not a pressure transducer after all. Anyway do you have any idea how I can find a way of compensating the reading of -0.000402 that is read by the pressure trans. even when no stress is given?...

 

Hi,
I need an answer as soon as possible because my VIVA is just around the corner (in June) and I haven’t really done any experiments yet with my spinning cylinder in the wind tunnel.


Everytime I switch on the power so that my Kyowa pressure transducer (that is in the middle of the cylinder) gives readings, there is a value that is not equal to zero (it always shows a value of about -0.000426 strain rate) eventhough the cylinder is not rotated yet and the wind tunnel is not switched on. Can anyone tell me how do I compensate for this so that the reading w/o stress could be zero?

Another thing, I heard about this offset nulling circuit. Can it be applied to my case? And this op amp, is it the same thing as the Kyowa pressure transducer that I am having?

Thank for your quick answers folks.......

is that "Viva Las Vegas"

you need a circuit to be able to modify it.

 

I see that Kyowa have data sheets and instruction manuals on their website, have you read them?

You need to explain your setup and include minor details like the type number of your pressure transducer to obtain any help.

Does your educational facility not explain/support your experiment?

 

Yes I have read the manuals , but nothing is being said about the compensation when no stress is given. The type of transducer is PS-1KDM8Z3K. It is not anymore on their website. I can give you the manuals if you want.

The setup is like this: the pressure transducer is connected to the slip ring (so that the transducer's wire in the rotating cylinder can rotate with it in the wind tunnel and the other end of the wire out side of the wind tunnel can stay stationary). This end is connected to the adapter NI 9949 which is then connected using the wire RJ-50 to the module which reads the signal from the transducer. The module is clipped into the NI chassis and this chassis is powered by electricity and another connection goes to the laptop for the data acquisition.

I am doing a master thesis, so I cant really depend on my supervisors for answers, or can I actually?

Anyways here is the manual.....

 

Isn't that what supervisors are for?

What are you doing your masters in?

 

Youre right , but I have problems with mine.

I am doing a research on spinning cylinders. The cylinder spins to generate lift and this lift is used to turn the rotor of the wind turbine to generate electricity. I am going to find out with which RPM the lift is the max. and whether the usage of a certain blockage in front of the spinning cylinder will generate extra lift......

 

No, I meant what field, such as Mechanical Engineering.

 

No.... I am doing Aeronautical Engineering.....

 

I guessed your subject was some branch of mechanical engineering so it is perfectly acceptable to seek help with the electrical aspects of a project.

You should receive plenty here.

As such we really need to know more of the details of the electrical setup. The mech stuff in the wind tunnel is interesting background only.

You may not realise that you have to connect any transducer (abbreviation Tx) to a signal conditioning amplifier before passing the signal to your recording and processing circuitry.

This interface amplifier is where you zero the signal.

Can you (or someone here?) draw a block diagram for us to work from?
Sorry I do not have the time right now.

 

We saw a similar situation here once before where someone working towards a PhD in Mechanical Engineering wanted us to show him all he needs to know about electronics in order to complete his research project.

I had to remind him that Electrical and Electronics are bona fida areas in engineering that people also spend years studying in order to earn an engineering degree.

For Aeronautical Engineering, I would suspect that a solid foundation in electricity and electronics would be a requirement. I suggest you take the time to learn the fundamentals.

Reading the tutorials found at the top of these pages would be a good starting point.

 

When I studied Electrical Engineering, I was required to take several courses in Mechanical Engineering. I'm surprise the OP wasn't required to some electronic courses as part of his education.