BS ISO 4360:2020

What is ISO 4360 about?  

ISO 4360 specifies methods for the measurement of the flow of water in open channels under steady flow conditions using triangular profile weirs. The flow conditions considered are steady flows which are uniquely dependent on the upstream head and non-modular (drowned) flows which depend on downstream as well as upstream levels. 

Who is ISO 4360 for?  

ISO 4360 on open channel flow measurement using triangular profile weirs is beneficial for  

• Fluid engineer 
• Fluid testing laboratory 
• Hydrologist 

Why should you use ISO 4360?  

Triangular weirs are commonly used to measure discharge in open channel flow. 

ISO 4360 provide guidance on installation conditions, measurement of the head(s), modular (free) flow, non-modular (drowned) flow, discharge characteristics, uncertainties of flow measurement required to measure the flow of water using triangular profile weirs. 

As a user of ISO 4360, you can efficiently determine the flow of water in open channels under steady flow conditions using triangular profile weirs. ISO 4360 helps the user to acquire knowledge on triangular profile weirs. ISO 4360 also guides the user on the type of flow, velocity distributions, required in the approach channel 

What’s changed since the last update?  

BS ISO 4360:2020 supersedes BS ISO 4360:2008, which is withdrawn. 

The main changes compared to the previous edition are as follows. 

• The calculations and examples have been updated to correct an error in the previous edition. 
• A URN has been added containing a spreadsheet that has been developed to support the standard and facilitate the calculation of discharge and uncertainty (see Annex C).