for my research work I want to assemble am instrument which has to measure a water depth of maximum 50cm minimum 15cm based on ultra sound principle.By training I am a civil engineer I seek information from people so that will find success in my work

 

Rather than trying to measure the depth, can you measure the surface level and then calculate the depth? Does the depth change because the top surface level changes or because the bottom changes? Why do you have to use ultrasound?

John

 

You need to specify your problem more carefully. How fast does the measurement have to be made, how accurate, what output form, how much money can you spend, etc.? Does the water's surface change quickly or slowly; is it agitated or not? Is the water turbid or clear? What's its conductivity, temperature, and any other relevant physical properties? Tell us what you will do with the resulting experimental data.

Focus first on the decisions that you will make with the data and design the decision process first, something that many experimenters never even consider (I mean understand and spec the statistical properties of your decision process). If appropriate, also learn something about the statistical design of experiments to help drive how you manage your experimental work. All this design information can then drive various technology choices. Unfortunately, most experimenters focus on the interesting technical details first and don't consider the big picture; this often results in painting oneself into a corner (or at least getting some paint on your shoes). Trust me, I learned this the hard way like everyone else does.

 

Rather than trying to measure the depth, can you measure the surface level and then calculate the depth? Does the depth change because the top surface level changes or because the bottom changes? Why do you have to use ultrasound?

John

The depth of water is constant 50cm below this water sand depth can vary from 15cm to 35cm,I want to measure that depth variation, can I use ultrasound priciple
Wilbertrk

 

The OP has opened another thread with a restatement of the question - http://forum.allaboutcircuits.com/showthread.php?t=39297