The King Instrument 7511 series flowmeter utilizes a float and tapered tube design. As a result, the King Instrument 7511 series rotameter has longer and more linear scales, better pointer stability, and 40% greater accuracy than competitively priced products. In addition, the King Instrument 7511 series flowmeter is precision-machined from durable cast acrylic stock and have 316L stainless steel internal components and fittings (brass fittings optional). The King Instrument 7511 series flowmeter is available in scales ranging from 2" to 10" (50 to 250mm) for increased accuracy and repeatability. The standard O-ring is EPR with optional Buna-N and Viton® alternatives. Series 7511 offers the following scale ranges; 7 GPH to 20 GPM and 2.6 SCFH to 60 SCFM. Accuracy is ± 6% of full scale flow for 50mm scale, ± 5% of full scale flow for 65mm scale, ± 4% of full scale flow for 100mm scale, ± 3% of full scale flow for 127mm scale and ± 2% of full scale flow for 250mm scale. Turndown is 10:1 and repeatability is 3% for 50mm scale, 2% for 65mm, 100mm and 127mm scale and 0.5% for 250mm scale.