Common use of Densitometers Clause in Contracts

Densitometers. A. Densitometers with frequency output shall be installed and proved in accordance with the API MPMS, Chapter 14, Section 6. The frequency output may be driven directly into a flow computer capable of internally converting frequency to corrected flowing density in gm/cc, or to a separate frequency converter and into the flow computer as a 4-20 ma signal. Proving is to be by entrapping a sample of the flowing stream at system conditions in a double-walled high-pressure vessel known as a pycnometer. The connections for the pycnometer shall be installed in the same manner as those of the densitometer. Thermowells shall be installed to allow monitoring of the inlet and outlet temperatures. Accuracy of the densitometer shall be verified at the time of the meter proving or when accuracy is in question. The accuracy of the densitometer shall be within +/- 0.001 gm/cc over its entire range and repeatable to +/- 0.0005 gm/cc.