NewPing Library: HC-SR04, SRF05, SRF06, DYP-ME007, Parallax PING))) - v1.7

The 1 pulse / 10uS width is just to trigger the sensor. The sensor detects this and then sends out it's own multiple pulses. In other words, the sensor doesn't just send out one 10uS pulse, we just trigger it. I have not seen a sensor that doesn't automatically send out multiple pulses from a trigger.

i know it how the sensor works but this sensor dosnt operate with 1 pulse / 10 us it works with 16 pulses with period of 21us and frequency of 40KHZ if i can apply this to my sensor it will work, now i just want to know how should i produce this 16 pulses(40KHZ)

Do you even know the maximum sensor distance? Maybe it's only 40cm

the maximum is 5 meter , it reads 40cm but not accurate it has 13cm error.