Differential pressure comparison from 5 Pa to 500 Pa with a liquid column manometer between CENAM (Mexico) and INTI – Fisica y Metrologia (Argentina)

• CENAM and INTI differential pressure comparison 5–500 Pa, October 2010–February 2011.
• SIM supplementary comparison, SIM.M.P-S6. The TS was a liquid column manometer.
• CENAM used 2 pressure balances (50 mm diam.), INTÍs a Junkalor, Dessau, Diving Bell.
• The TS was adequate for the purposes of this comparison.
• En was used to compare the results. There is compatibility between the laboratories.

A differential pressure comparison was performed between CENAM (Mexico) and INTI (Argentina) by means of a liquid column manometer. The measuring range was 5–500 Pa. CENAM calibrated the transfer standard at the beginning and at the end of the comparison. The transfer standard used was a Dwyer liquid column manometer model Microtector with an accuracy class of 0.013% of the reading. The compared pressure points were (5, 75, 125, 200, 250, 300, 350, 400, 450, 500) Pa. The uncertainty sources to be evaluated included at least the following: (a) Uncertainty due to the standard used by the laboratory; (b) Uncertainty due to repeatability; (c) Uncertainty due to resolution; (d) Uncertainty due to hysteresis; (e) Uncertainty due to zero drift. The criteria used to compare the results obtained were the normalized error equation (En). The results obtained by the laboratories were compatible according to the criteria |En| ⩽ 1.