The linear flow range of the EFR design precision turbine flowmeter is +/-15:1. Measurement range can be extended to reasonable amounts above and below the linear capabilities of the PTF, but the user must be conscious of trade-off in accuracy.
Repeatability can be achieved outside of linearity, thereby extending the flow range, but these issues should be considered carefully in light of expected performance. This physical limitation is characteristic of all turbine meter designs.