Abstract: A gas flow rate verification apparatus is provided for shared use in a multiple tool semiconductor processing platform. The gas flow rate verification apparatus is defined to measure a pressure rate of rise and temperature within a test volume for determination of a corresponding gas flow rate. The apparatus includes first and second volumes, wherein the second volume is larger than the first volume. The apparatus also includes first and second pressure measurement devices, wherein the second pressure measurement device is capable of measuring higher pressures. Based on the target gas flow rate to be measured, either the first or second volume can be selected as the test volume, and either the first or second pressure measurement device can be selected to measure the pressure in the test volume. Configurability of the apparatus enables accurate measurement of gas flow rates over a broad range and in an time efficient manner.