LR-Cal LDW-HK, Руководство пользователя, Страница: 32 / 92

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6. Commissioning, operaon
Default condions are input at but once the user alters these, his Leitenberger
values then become the default (no need to repeatedly insert your values).
6.9 Temperature measurement of piston units
For many purposes, such as calibrang most type of dial gauges and transducers,
accurate knowledge of the temperature of a piston unit is not necessary. However, in
order to achieve the utmost accuracy from a pressure balance it is important to know the
temperature of the piston unit as close as possible to the working part of the unit.
In laboratories where the room temperature is controlled it is most likely that the
temperature of the working parts of the unit will not dif er from the ambient temperature f
by more than 0.5 °C. When working in uncontrolled temperatures, however, one would
have to measure the temperature of the piston unit.
A possible way to do this is to use a disc shaped thermistor type probe sensing element
taped to the outer surface of the piston unit. The sensing element should be insulated
from the ambient temperature by covering the element with a thin strip of polystyrene,
or other insulang material, then taping this to the piston unit.
6.10 Cleaning gauges
This cleaning/degreasing process is only suitable for use with pressure gauges with
either phosphor bronze, beryllium copper, monel or stainless steel bourdon tubes in the
form of a "C".
It is not advisable to degrease pressure gauges with steel bourdon tubes since a very
small amount of corrosion on the bore of a bourdon tube can cause inaccuracies of
reading and early failure of the tube.
Manual M LDW-HK odel LR- Cal