measurement device fluid pressure regulator LSR2 fluid pressure regulator Part of the fluidic subsystem. The fluid pressure regulator maintains constant pressure within the sheath and or sample lines by filling the lines with enough gas to push the fluid at the desired rate. The gas is usually air, and less frequently nitrogen. In the sheath line, the gas is pushed into the sheath tank. In the sample line the gas is pushed into the collection tube. Fluid pressure regulators maintain great enough pressure to push sample fluid out of the tube and sheath fluid out of the sheath tank. Person: John Quinn Practical Flow Cytometry 4th Edition, Howard Shapiro, ISBN-10: 0471411256, ISBN-13: 978-0471411253 fluid pressure regulator