Vega DSGH, Operating Instructions Manual

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28 DSGH Installation and Operation Guide
Installation
necessary, you can physically mount the density gauge apart from the
vessel or pipe, but notify VEGA at the time of the order to ensure proper
source size and shielding.
Stable temperature
Mount the gauge on a portion of the line where the temperature of the
process material is relatively stable. Process temperature can effect the
gauge indication. The amount of the effect depends upon the following:
• Sensitivity of the gauge
• Temperature coefficient of the process material
Temperature compensation is available, but requires an VEGA
temperature probe in the process as an input to the gauge.
Protect insulation
If insulation is between the measuring assembly and the process,
protect the insulation from liquids. The absorption of a liquid, such as
water, can affect the gauge indication because it blocks some radiation.
No air entrainment
Mount the gauge on a portion of the line where there is no possibility of
air or gas entrainment and where the pipe is always full of process
material.
Air or gas entrainment in the process or a partially full pipe, can result in
an inaccurate gauge indication.
Standardization considerations
The gauge requires periodic standardization. Use process, absorber
plates, or other easily repeatable reference fluid, such as water, for this
standardization. You must be able to empty or fill the pipe with water if
you plan to standardize with absorber plates or water. Often, you can
purge the measuring section of a pipe by rerouting the process material
through a bypass section.