How to I calculate limit error on fuel dispenser ?

To calculate the limit error on a fuel dispenser, you will need to follow these steps:

1. Determine the maximum allowable error for the fuel dispenser. This information can usually be found in the manufacturer's specifications or regulations set by the relevant authorities.

2. Measure the actual amount of fuel dispensed by the dispenser using a calibrated measuring container. Make sure to dispense a significant amount of fuel to get an accurate measurement.

3. Calculate the difference between the actual amount dispensed and the intended amount (as displayed on the dispenser).

4. Divide this difference by the intended amount and multiply by 100 to get the percentage error.

5. Compare the percentage error to the maximum allowable error to determine if the dispenser is within the acceptable limits.

If the percentage error exceeds the maximum allowable error, the dispenser may need to be recalibrated or repaired to ensure accurate fuel dispensing.

Calculating Limit Error on a Fuel Dispenser

Step 1: Collect Data

- Measure the amount of fuel dispensed by the dispenser into a calibrated container.
- Record the measured volume, the volume displayed on the dispenser, and the environmental conditions (e.g., temperature, barometric pressure).

Step 2: Calculate Mean Error

- Calculate the mean error by taking the difference between the measured volume and the displayed volume for each measurement.
- Find the average of all the mean errors calculated.

Step 3: Calculate Standard Deviation

- Calculate the standard deviation of the mean errors to determine the variability of the measurements.

Step 4: Determine Limit Error

- The limit error is calculated by multiplying the standard deviation by a factor that depends on the confidence level desired and the number of measurements taken.
- For a 95% confidence level and over 30 measurements, the factor is 2.

Formula for Limit Error:

```
Limit Error = 2 - Standard Deviation
```

Example:

- Measured Volume: 10.00 liters
- Displayed Volume: 10.02 liters
- Mean Error: 0.02 liters

If you have 30 or more measurements with a standard deviation of 0.01 liters, the limit error would be:

```
Limit Error = 2 - 0.01 liters = 0.02 liters
```

Interpretation:

- The limit error indicates the maximum permissible error for the fuel dispenser at the 95% confidence level.
- If the limit error is exceeded, the dispenser may need to be recalibrated or serviced.