WIKA CPB3800 - Handbuch (Seite 32)

32 WIKA operating instructions model CPB3800
14062232.03 12/2013 GB/D
GB
6. Commissioning, operation
Default conditions are input at DH-Budenberg/WIKA but once the user alters these, his
values then become the default (no need to repeatedly insert your values).
This program has been written to aid users to maintain the standard
accuracy of DH-Budenberg/WIKA pressure balance. It has not been
written for use with any other makes of pressure balance.
The software can be accessed from the supplied CD in the folder "Customer Software"
and "Standard Accuracy DWT". Installation/Operating instructions should be read
before using the software.
6.9 Temperature measurement of piston units
For many purposes, such as calibrating 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 differ from the ambient temperature
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 insulating material, then taping this to the piston unit. Alternatively, a model
CPU6000 CalibratorUnit may be used.
We can supply a suitable instrument. Please contact DH-Budenberg/WIKA.
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.