Ultrasonic Distance Sensor

The Aranet Ultrasonic Distance Sensor measures distance using ultrasound time-of-flight.

It emits a high-frequency pulse. It then measures the return time.

Use it on liquids and solids. Common use cases include tank level and silo fill.

Pairing and configuration

After you pair the sensor to a Base Station, open the sensor settings.

You can configure:

• Measurement thresholds for alerts and automation.
• A reference point (zero) for level-style readings.

Converting distance to your units

Turn on Conversion. Then pick Units from the drop-down list.

Set the Zero reference point:

• Enter it manually, or
• Click USE CURRENT MEASUREMENT to capture the current reading as zero.

Pick a zero that matches how you interpret “empty” or “full”. For example, set zero at the distance to an empty tank bottom.

Placement tips

• Keep a clear line-of-sight to the target surface.
• Mount the sensor stably and square to the surface.
• Avoid measuring through heavy foam, splashing, or moving parts.

Specific conversion notes

To show the correct stem diameter value with the Stem Micro-Variation sensor, it is necessary to configure it upon installation. The process can be done in the following steps:

1

Correct measurement of the stem

First existing stem diameter should be measured with a ruler or caliper (for example, 8mm)

2

Accordingly, mount the detecting element on the stem.

3

Check for a reading in the WebGUI

The sensor's electric current reading on the Aranet base station graphical user interface should be checked and recorded (for example, 5.12mA)

4

Determine measurement range

Next, it is necessary to determine how much of the sensor measurement range (4–20 mA) is already used by the current measurement.

Here, from the recorded current value, the minimal reading value = 4mA, should be subtracted (for example, 5.12 mA – 4 mA = 1.12 mA)

5

Perform calculations

The subtraction value obtained in the previous point should be divided by 0.01mA, which is the resolution step of electric current measurements (for example, 1.12mA/0.01mA = 112).

This is the measurement range in step units that are already used by the sensor.

Next, the used electric current measurement step unit value should be multiplied by 0.003125mm, which is the value of one measurement step unit in millimeters (for example, 112*0.003125mm=0.35mm).

The obtained value should be rounded to 2 digits after the comma, and it is the measurement range used by the sensor in millimeters (for example, 0.35mm);

Next, the used measurement range in millimeters should be subtracted from the stem diameter measured in step 1 (in our example 8mm-0.35mm=7.65mm), and here we obtain the stem diameter value that corresponds to a 4mA electric current reading of the sensor.

Then the measurement value in millimeters should be determined to correspond to max electric current measurement value of 20mA. Sensor measurement range in millimeters is 5mm, so this value should be added to the value obtained in step 7, to get the value corresponding to the 20mA electric current reading of the sensor (for example, 7.65mm + 5mm=12.65mm)

6

Enter the results of calculations

Finally, previously obtained millimeter values for 4mA and 20mA should be entered in Stem Micro-variation sensor Conversion configuration in the Aranet base station graphical user interface section Sensors → SENSORS, after that, the user will be able to see sensor measurements in mm of the stem diameter: