Cook Plant preoperational studies, 1969 / John C. Ayers ... [et al.].

The resulting relative humidities have variations that may be within the
range of error of the instrument under ideal conditions for reading the thermometers. They are considered meaningless under the conditions of difficult
posture and need for speed that were involved in the field conditions.
A remote-reading and recordable dew-point sensor has been found and will
be tried during the spring and early summer of 1970. This instrument is capable,
in the laboratory, of detecting significant difference between the dew-point
and relative humidity of air close above the rim of a container, half full of
water, and air in the upper half of the container below the rim. This sensor
is readily adaptable to mechanical raising and lowering at reasonable distance
from the ship's side in the upwind airflow. The readings would then not be
modified by the presence of the ship. The instrument will be used in traverses
across plume axes to determine whether variations in dew-point or relative
humidity can be shown between conditions in the axis of the plume and the
ambient water on either side of the plume. If it can detect such variations
in the field, it will be used to map the over-plume vs over-ambient dew-point
and relative humidity conditions in three dimensions.
In summary, our present thermistor temperature sensors may or may not be
able to demonstrate the flow of sensible heat from plume water to air. If heat
flow can be measured, it will be by showing differences in vertical rates of
cooling in the bottoms of air columns over plumes vs the conditions in the
bottoms of air columns over ambient water outside the plumes. If traverses
across plumes cannot show different air cooling rates over the plume and outside,
we will have to go to different sensors; the very sensitive thermocouples are
an obvious first choice. Our standard aspirated psychrometer may be sufficiently
sensitive to demonstrate increased flux of water from plume to air, but it is
ruled out by requiring the presence of the human eye at the same altitude.

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