present invention when the regulator adjusts the line pressure to reflect the change in atmospheric pressure this is immediately sensed by the pressure sensing means 30 within chamber 24 and by means of the link transfer assembly 42 the ring 74 of the continuous integrator assembly 36 is repositioned on disc 66 to impart to roller 76 the proper representative rotational speed and thus the corrected counter 54 will reflect the volume of the gas corrected to the standard or base pressure the absolute pressure continuous integrator 10 has an operative pressure range of 0 45 psig that is made possible by the use of the novel knife edge groove support assembly 88 depicted in fig3 and 4 diagrammatically represented in fig6 the vacuum pressure chamber assembly 12 has an annular dimple 132 formed on its upper surface and in which is fitted an upper support 134 which is soldered thereto as at 136 so as to form a seal therebetween the upper support 134 has a central opening 138 the lower portion of which terminates in an upper sleeve 140 a 34 v 34 groove 142 is formed on diametrically opposite sides of the undersurface of the upper sleeve 140 the upper support 134 is counterbored as at 144 to form a guide sleeve 146 which extends upwardly through the annular dimple 132 and is joined thereto by the soldered seal 136 the top of the guide sleeve 146 is open and the bottom terminates in a shoulder 148 the upper support 134 has a radial flange 150 which rests on the underside of the dimple 132 within the chamber 24 and the lower portion thereof defines an annular shoulder 152.