In short
Calibrating a fuel tank means filling it in measured portions and writing down the sensor reading after each one, which gives a table that turns the raw signal into litres.
For most tanks use 10 to 20 portions and let the fuel settle for 2 to 3 minutes after each. Planva loads calibration tables for fuel level sensors from CSV or XLSX files and shows refills and drains in the machine task.
Why a sensor needs a table
A fuel level sensor measures the level of fuel at one point and reports it as a voltage or a digital value. The shape of the tank decides how that level maps to volume, so the same reading means a different number of litres in different tanks. The calibration table pairs each reading with a volume, and the monitoring platform uses it to convert level readings into litres.
Before you start
- Work safely. Fuel vapour ignites. Keep ignition sources away from the tank and follow your site rules for handling fuel.
- Empty the tank. The first row of the table is the reading at zero litres.
- Check the power. Make sure the vehicle battery is charged and will not run down during the procedure.
- Install the sensor as the manual says. Calibrate only a sensor that is fixed in its final position.
- Set the tracker to save data at least every 10 seconds. You will need several messages after each portion.
- Turn off smoothing. The Escort manual for its TD-150 sensor says filtering is set to zero during calibration and is switched on only afterwards.
- Prepare a two-column sheet. One column for the sensor reading, one for litres, plus the start time.
The procedure
- Record the empty reading. Write the sensor value with zero litres. This is row one.
- Divide the tank into 10 to 20 portions. Wialon gives this range, and it matches the table below.
- Add one measured portion. Use a transfer pump with a meter or a fuelling point that dispenses a known volume.
- Wait 2 to 3 minutes. Let the level settle and let the tracker log a few more messages.
- Record the reading and the total volume. Take the sensor value as described in the next section.
- Repeat until the tank is full. The last row is the full tank.
How big a portion
Navixy asks for 10 to 20 entries or more, which means a portion of one tenth to one twentieth of the tank volume, with one twentieth preferred. Its table by tank size is below.
| Tank capacity | Portion, litres | Table entries |
|---|---|---|
| 0 to 100 L | 5 to 10 | 10 to 20 |
| 101 to 500 L | 10 | 10 to 50 |
| 501 to 1000 L | 20 | 20 to 50 |
In the last row the arithmetic is tighter than the printed range. At 20 litres per portion a tank of 501 to 1000 litres needs roughly 25 to 50 portions, so treat 20 as a floor. If the tank has a complex shape, halve the portion where the level passes through the awkward area, so the table follows the curve.
Taking the reading
- Use the logged messages. Find several messages from 2 to 3 minutes after each portion, and average the sensor value.
- Skip the voltmeter. Wialon advises against it for analog sensors because of voltage drop in the circuit and differences in accuracy.
- Read digital sensors in the configurator. Take the value from the sensor software.
Mistakes that spoil a table
- Portions that are not measured. The litres column is only as good as the meter that filled it.
- Reading too early. Fuel that is still moving gives a reading that does not belong to the volume you entered.
- Smoothing left on. The Escort manual keeps it off until calibration is finished.
- Too few rows. Navixy asks for 10 to 20 entries or more.
- A reading that falls. As fuel is added the values should keep moving the same way. A row that breaks the order points to a bad reading, so repeat that portion.
How this works in Planva
- Machine card. Fuel type, consumption norm, engine hours and working width.
- Trackers. Calibration tables for fuel level sensors load from CSV or XLSX.
- Machine task. Refills and drains from the sensor appear next to the track and the area.
You run the calibration with the sensor software or by hand, then load the table. Planva does not calibrate the sensor. To turn the data into litres per hectare, read tractor fuel consumption, and for the platform side see farm machinery tracking.
Sources
Common questions
Empty the tank and record the reading, then add measured portions of fuel one at a time. Wait 2 to 3 minutes after each portion, record the reading and the total litres, and repeat until the tank is full.
The real Planva interface, shown with test data.
