4/9/98
A-2
Application of the Hygrometer (900-901D1)
Moisture Monitor Hints
GE Panametrics hygrometers, using aluminum oxide moisture
probes, have been designed to reliably measure the moisture
content of both gases and liquids. The measured dew point will
be the real dew point of the system at the measurement location
and at the time of measurement. However, no moisture sensor can
determine the origin of the measured moisture content. In
addition to the moisture content of the fluid to be analyzed, the
water vapor pressure at the measurement location may include
components from sources such as: moisture from the inner walls
of the piping; external moisture through leaks in the piping
system; and trapped moisture from fittings, valves, filters, etc.
Although these sources may cause the measured dew point to be
higher than expected, it is the actual dew point of the system at
the time of measurement.
One of the major advantages of the GE Panametrics hygrometer
is that it can be used for
in situ
measurements (i.e. the sensor
element is designed for installation directly within the region to
be measured). As a result, the need for complex sample systems
that include extensive piping, manifolds, gas flow regulators and
pressure regulators is eliminated or greatly reduced. Instead, a
simple sample system to reduce the fluid temperature, filter
contaminants and facilitate sensor removal is all that is needed.
Whether the sensor is installed in situ or in a remote sampling
system, the accuracy and speed of measurement depend on the
piping system and the dynamics of the fluid flow. Response times
and measurement values will be affected by the degree of
equilibrium reached within system. Factors such as gas pressure,
flow rate, materials of construction, length and diameter of
piping, etc. will greatly influence the measured moisture levels
and the response times.
Assuming that all secondary sources of moisture have been
eliminated and the sample system has been allowed to come to
equilibrium, then the measured dew point will equal the actual
dew point of the process fluid.
Содержание PM880
Страница 1: ...PM880 Portable Hygrometer ...
Страница 38: ...August 2003 2 18 Initial Setup Keypad cont Figure 2 8 The PM880 Keypad ...
Страница 150: ...August 2003 8 4 Servicing the PM880 Printing Reports cont Figure 8 3 Printout of a Typical Drive Report ...
Страница 237: ...5 August 2003 Index cont K K PPMv 3 17 Keypad Description 2 17 Key Description 2 17 Keys Description 2 17 ...