TIME OF FLIGHT

The Time-of-Flight (also Transit-time) method uses the change in sonic velocity with and against the direction of flow. It is: v = d*(t2-t1)/(2*t1*t2) = ca. c2/(2d*cosb)*(t2-t1) That means: high resolution demands high precision time-measurement - especially for small flow velocities. Take an example: we want to measure a flow of 0,5m/s in water (c=1480m/s at 20°C) with a resolution of0.5%. The distance between the two ultrasonic transducers may be 10cm at an angel of 45°. The final time difference is then 33ns. The needed resolution is 165ps - for the TDC-GP2 with its 65 ps single shot resolution this is no problem!

• Integrated fire pulse generator for up to 15 pulses with programmable phase and

• Industrial operating range: from -40°C to 125°C

• Battery applications: Discover the TDC-GP2 - it's perfect for this! The total current of the measuring unit can be decreased down to 3 to 5 µA.

• Supply voltage range: 1.8V to 5.5V

• Temperature measurement: The intergrated temperature measurement unit allows to measure the cold and hot water temperature with 0.002 °C resolution at 50 times less current than A/D converter solutions

• Small size: Single-chip solution in the small QFN32-package (5x5 mm²)