Abstract： ASME PTC 22:2005 pdf download.Gas Turbines. (C) If there are any changes in location of instrumentation, then this must be documented including recording the relocation of items in the process variable ioop routing during the design and/or...

ASME PTC 22:2005 pdf download.Gas Turbines.

(C) If there are any changes in location of instrumentation, then this must be documented including recording the relocation of

items in the process variable ioop routing during the design and/or the construction phase of the plant. Any impact on test

uncertainty should be identified and reviewed with consideration to Code limitations. An example is the relocation of a flow meter within a process line.

(d) The applicability of the instrumentation should be considered for measuring the desired test process value. Note whether the

recorded value is an instantaneous or average value. Note also the historical logging capabilities necessary for the testing.

(e) Access and isolation capability is required for inspection, calibration, and any temporary instrument installation and removal.

(f) Review the quantity of devices and instrument ports available at each location to reduce uncertainty and provide contingency

data acquisition. An example is using two (2) single or one dual element thermocouple to measure critical temperatures.

(g) Layout the instrument mops to minimize measurement error. Precautions are listed in Section 4 of this Code. If instrument

translormers are used, adequate wire size should be used to reduce voltage drops and a neutral cable should be provided to enable

accurate 3- phase watt metering.

(h) The design should include the ability to duplicate critical test measurements. This allows a validation of process values and

includes a contingency plan for test measurements. A separate device should be identified to collaborate and backup a test

measurement.

(I) A review should be performed of the water leg correction necessary for accurate process variable measurement.

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