| region_pTReturn the current region (valid values: 1,2,3,5) in IF97, given pressure and temperature |  | 
| p | Type: Pressure (Pa) Description: Pressure | 
|---|---|
| T | Type: Temperature (K) Description: Temperature (K) | 
| mode | Default Value: 0 Type: Integer Description: Mode: 0 means check, otherwise assume region=mode | 
| region | Type: Integer Description: Region (valid values: 1,2,3,5) in IF97, region 4 is impossible! | 
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