Flowmeters - Turndown Ratios
Calculate turndown ratio (rangeability) for flow measurement devices like orifices and venturi meters. Turndown ratio compares the maximum flow to minimum flow to determine the span or range of flow measurement devices.
Turndown Ratio Calculator
Turndown ratio (Rangeability) is used to compare flow measurement devices. It is expressed as:
TR = qmax / qmin
Where:
- TR = Turndown Ratio
- qmax = maximum flow
- qmin = minimum flow
The turndown ratio is typically expressed as a ratio (e.g., 4:1).
Example
For an orifice meter with maximum flow of 12 kg/s and minimum flow of 3 kg/s:
- TR = 12 / 3 = 4 (expressed as 4:1)
Typical orifice plates have turndown ratios between 3:1 and 5:1.