Ultrasonic Calculator Inputs
Example Data Table
| Case | Mode | Medium | Temperature | TOF | Angle | Offset | Reference Distance |
|---|---|---|---|---|---|---|---|
| Air target | Pulse-Echo | Air | 20 °C / 50% | 3000 µs | 0° | 0 m | 0.516 m |
| Angled scan | One-Way | Air | 25 °C / 60% | 1200 µs | 10° | 0.01 m | 0.420 m |
| Water path | Pulse-Echo | Water | 20 °C | 800 µs | 0° | 0 m | 0.593 m |
| Steel inspection | Pulse-Echo | Steel | 20 °C | 100 µs | 30° | 0 m | 0.258 m |
Formula Used
Distance = (c × t) / 2
Distance = c × t
c ≈ 331.3 + (0.606 × T) + (0.0124 × RH)
Perpendicular Distance = Beam Path × cos(θ)
Reference Distance = Perpendicular Distance + Sensor Offset
Here, c is sound speed, t is time of flight, T is temperature in °C, RH is relative humidity in percent, and θ is beam angle from the normal direction.
How to Use This Calculator
- Select whether you want distance, time, or sound speed.
- Choose the measurement mode: pulse-echo or one-way.
- Select a preset medium or enter a custom sound speed.
- Enter environmental conditions for air or water use cases.
- Provide time of flight, known distance, or both, depending on the selected calculation type.
- Apply beam angle and sensor offset when your setup is not perfectly normal or the sensing face is not your reference plane.
- Press Calculate to show the result above the form.
- Use the graph and export buttons to document the measurement.
Frequently Asked Questions
1. What is pulse-echo mode?
Pulse-echo mode sends a pulse to the target and listens for the return echo. The sound travels to the target and back, so the time path is doubled.
2. When should I use one-way mode?
Use one-way mode when separate transmitter and receiver positions are used, or when your system measures direct travel without a returning echo.
3. Why does temperature matter?
Temperature changes the speed of sound, especially in air. Even modest temperature shifts can introduce noticeable distance error over longer travel paths.
4. Why is humidity included for air measurements?
Humidity slightly changes air density and sound speed. The correction is smaller than temperature correction, but it can still improve repeatability in careful measurements.
5. What does beam angle correction do?
An angled beam travels farther than the perpendicular stand-off distance. The calculator converts beam path length into the shorter normal distance using the cosine relationship.
6. When should I use custom sound speed?
Use a custom value when your transducer, material, mixture, or calibration certificate gives a measured sound speed different from the listed presets.
7. What is sensor offset?
Sensor offset accounts for physical spacing between the sensing face and the real measurement reference point, such as a bracket edge or mounting plane.
8. How accurate are the results?
Accuracy depends on timing resolution, alignment, medium stability, transducer calibration, and environmental compensation. Treat results as engineering estimates unless validated against known references.