please help me pzt oscilloscope signal

https://drive.google.com/open?id=1Czia2YBXcpnFNUdYOyggPbE9l4HmXpBJ https://drive.google.com/open?id=1KkPFeC1w6cdSDlFw9EHPkkPEt5-bzzjG

this is signal graph https://drive.google.com/open?id=1RL3-6gSHURQO02v4HPX6I1Wf2IVCtG08

and pzt property https://drive.google.com/open?id=0B_sEcZXEBGo0SXViNFJOeHJrTjgtbkp0MnFkbzN3SkVjQ0ZB

First, (last file), I couldn't understand why the current is flowing through side but direction of movement is another way.

Second, I can understand the oscilloscope graph (third file) first one but at second one, why graph is like that?

and want to know direction. does Ultrasonic is going to the way that same direction of pulse current or another way???

Pulse signal is 500KHz and generated by arduino uno. First and second picture is pzt in third picture.

What does pzt mean ?

pzt is piezoelectric. (metarial) that can generate ultrasonic wave or something.

Hello dongjee33,

A lot of people on here, myself included, are not keen to click on links to random web sites to get information about things people are asking about. Partly because I think 'why should I, you want the help' and partly because of the risk of viruses and other crap from sites I know nothing about. Please read 'how to use this forum-please read', especially section 8 and 9 about posting attachments and images, then go back and modify your original post. You are more likely to get help that way.

Thank you.

@dongjee33

What you have to realise is that you know what this project is all about, it is in your head and in front of you. Nobody else has the slightest clue about what you are doing, and until you can communicate that with us then we don't stand a chance of being able to help you with the best will in the world.

Please do what Perry says and Please read all of this:- How to use this forum