Turndown ratio\u2014sometimes called \u201crangeability\u201d\u2014is one of the most important yet frequently overlooked parameters when selecting a flow meter. Although engineers often focus on accuracy, pressure rating, or compatibility, the turndown ratio determines whether a flow meter can reliably measure flow across the full range of operating conditions. A misunderstanding of this parameter can lead to poor measurement accuracy, unstable readings, or even complete system failure.<\/p>