The Ultrasonic Level Transmitter Distance Calculator helps calculate the distance between an ultrasonic level transmitter and the surface of the measured object. Ultrasonic transmitters are commonly used in industries for non-contact level measurement of liquids, solids, and slurries. They emit ultrasonic pulses that reflect off the surface of a material and then measure the time taken for the echoes to return to the transmitter.
Formula for Ultrasonic Level Transmitter
The formula used to calculate the distance (D) between the sensor and the object is:
Where:
- D: Distance between the sensor and the object (in meters)
- c: Speed of sound in the medium (in meters per second)
- t: Time difference between the transmitted pulse and the received echo (in seconds)
Why Divide by 2?
The ultrasonic pulse travels to the object and back to the sensor. The measured time (t) is for the round trip (from the transmitter to the object and then back to the transmitter). To calculate the one-way distance from the sensor to the object, the round-trip time is divided by 2.
How to use this Calculator
1. Input the Speed of Sound:
The speed of sound in a medium varies based on factors such as temperature, humidity, and the type of medium. For example:
- In air (at 20°C or 68°F), the speed of sound is 343 m/s.
- In water, it is around 1482 m/s.
- In oil, it is approximately 1200 m/s (depending on the type of oil).
If you know the exact speed of sound for your application, input that value.
2. Enter the Time Difference:
The ultrasonic transmitter emits a pulse, and the time difference is the duration between the emission and reception of the echo. This value is typically measured by the ultrasonic transmitter and is expressed in seconds.
3. Calculate:
After entering the speed of sound and the time difference, the calculator will compute the distance (D) between the transmitter and the object.
Step-by-Step Example:
Let consider a scenario where an ultrasonic level transmitter is measuring the level of liquid in a tank with the following data:
- Speed of sound in air: 343 m/s
- Time difference between the transmitted pulse and the received echo: 0.05 seconds
Using the formula:
So, the distance between the sensor and the liquid surface is 8.575 meters.
Click here for Understanding the Factors Influencing the Accuracy of Ultrasonic Level Measurement
Practical Considerations
Temperature Effects:
The speed of sound in air increases with temperature. For example:
- At 0°C, the speed of sound is about 331 m/s.
- At 20°C, it increases to 343 m/s.
Use appropriate correction factors if the temperature deviates significantly.
Medium Selection:
Different mediums have different sound speeds. Sound travels faster in liquids (such as water) and solids than in air. Ensure you select the correct speed of sound for the medium being measured.
Transmitter Installation Height:
If the transmitter is mounted on top of a tank or vessel and you need to calculate the material level, subtract the calculated distance from the total height of the tank to find the level inside.
For example, if the tank height is 10 meters and the calculated distance is 8.575 meters, the liquid level is:
Leve l = Tank Height−D
=10−8.575 =1.425 meters
Click here for Ultrasonic Level Transmitter Installation Checklist
Additional Features
Custom Speed of Sound:
For mediums other than air or water (e.g., oils or chemicals), you can enter a custom speed of sound for more accurate calculations.
Automatic Temperature Compensation:
Some ultrasonic level transmitters are equipped with temperature sensors to automatically adjust the speed of sound, ensuring more precise readings.
Common Applications of Ultrasonic Level Transmitters
- Tank Level Measurement: Measuring the level of liquids in storage tanks or silos.
- Open Channel Flow Measurement: Detecting water levels to calculate flow rates in open channels.
- Bulk Solids Measurement: Measuring the level of solids like grain, coal, or powders in silos.
- Non-contact Measurement: Ideal for measuring corrosive, abrasive, or contaminated materials without physical contact.
Here you can refer more Online Instrumentation Calculators Collections
