摘要 |
A diaphragm differential pressure unit having range springs and a zero spring to bias the diaphragms. One end of each range spring is fixed relative to the centers of the diaphragms. The other ends of the springs may be clamped to or unclamped from the unit body independently in any combination to increase or to decrease, respectively, the biasing force on the diaphragms. The force constants of four range springs are weighted thus: 21k, 22k, 23k and 24k, respectively, where k is nominally 62.5 pounds per inch. The zero spring is an adjustable spiral spring having a force constant at least of an order of magnitude lower than that of the 2k range spring. It is an outstanding advantage that the springs prevent the amplification of mechanical inaccuracies for different spring combinations and adjustments.
|