Bilateral comparison to support planned replacement of CMC entries of PTB in the range 1E-2 Pa to 2E3 Pa

Project Description

Two new pressure balances, the FPG of CMI and the FRS5 of PTB, both of which were evaluated as primary standards by determination of their effective area and their respective uncertainty budget, shall be compared by direct comparison of their readings when connected together in the same laboratory. A reasoning of the comparison is also to check, if there is any significant pressure dependence of the effective area. Since the two pressure balances are very different in their technical design, it is rather improbable that such a pressure dependence would result in the same pressure indications over the mentioned comparison range.

The comparison will be performed at the site of the vacuum metrology lab of PTB in Berlin.

Test gas will be dry nitrogen.

Each nominal pressure will be established at least 5 times and on at least two different days. Near 3000 Pa a rotating piston gauge may be used in addition.

Final Report 2007-05-31

The comparison has been completed and the results are available in the KCDB.