# Main Screen Data Interpretation

### **Instantaneous Flow Rate and Error Margin**

The maximum possible measurement error for this flow meter is:\
\&#xNAN;**±0.5% of Full Scale (F.S.) + ±2.5% of Observed Reading (O.R.)**.

This means that the relationship between **measured values and maximum possible error** will vary depending on the flow velocity, as illustrated in the reference chart.

<figure><img src="https://1029883065-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F1LFXmYU1oAy08IUwsTZc%2Fuploads%2FOI8zcrbvA8qq8SmvEQc7%2Fimage.png?alt=media&#x26;token=e8f076e1-edd8-4f0b-a999-a0a6bd005c2e" alt=""><figcaption></figcaption></figure>

### **Flow Velocity**

The flow velocity shown on this screen represents the **fluid speed inside the tee section** of the flow meter.\
In most cases, this value is **slightly higher** than the velocity in an equivalent straight pipe of the same diameter.

### **Totalised Flow and Historical Data**

The totalised flow display will **continue accumulating** until it is manually reset.\
The **maximum count** for totalised flow is **999,999,999 litres**.