Do all pressure transmitters have the same turndown ratio?
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Not all pressure transmitters have the same turndown ratio. This number might be very different for different types and brands. Also called rangeability, the turndown ratio tells you how much a transmitter’s measuring span can be cut down from its maximum range while still being accurate and working well.
For instance, a turndown ratio of 10:1 indicates that the transmitter can be set up to measure a range that is just one-tenth of its full width. Higher turndown ratios provide you additional options, so you can use the same transmitter for multiple applications with varied pressure ranges.
The Fuji Electric FCX-AIV line of smart pressure transmitters has advanced features and high turndown ratios, up to 100:1. This makes them very useful in dynamic process situations where pressure levels can change over time or where accurate low-pressure readings are needed over a broader area.
Some lower-end or older transmitters have restricted ranges or limited turndown capabilities, usually between 3:1 and 10:1. This makes them less flexible and may need you to choose multiple models for different process demands.
Always think about the measurement range you need, how often the process changes, and how often you might need to re-range when choosing a transmitter. A higher turndown ratio can save money by cutting down on the number of various transmitters needed in a facility. It can also make the system more flexible and better at what it does.