A measurement system 300 for precisely measuring the distance between two points includes a laser interferometer assembly 314 having a beam splitter 320 and a first reflector 322 disposed to reflect a laser beam along a linear path 302. The laser interferometer system 314 cooperates with a deadpath elimination cell 308 having a sealed hollow interior region 310 sealed by at least one window 312. A second reflector 328 is disposed on the opposite side of the hollow interior region 310 and is oriented to reflect the laser beam back along the linear path 302. Thus, the volume and quantity of gas within the hollow interior 310 remains constant to increase the accuracy in measuring the distance between the first and second reflectors 322, 328.
