Vaisala Hydromet Data Collection Platform - Manual (Page 156)

User's Guide ______________________________________________________________________
154 __________________________________________________________________M210784EN-E
Celsius scale Temperature scale having the freezing point of pure water at 0 °C and
the boiling point at 100 °C under standard sea level pressure. All the
temperatures measured with the QML logger are given in Celsius
degrees.
Configuration Set of instructions for the QML logger. The compiled setup (a script)
is in fact a program that runs in the logger.
Crosswind The wind blowing perpendicular to the course of a moving object.
Damping ratio Describes the response of a wind vane to a sudden change in wind
direction. It is defined as the ratio of the actual damping to the critical
damping. Critical damping is that value of damping which gives the
fastest transient response without overshoot.
Delay distance The passage of air necessary over a wind vane to cause the vane to
respond to 50% of a step function change in wind direction.
Dew point
(temperature) The temperature at which the air, if cooled, would reach saturation,
and at which dew would therefore begin to condense out on a solid
surface.
Global radiation The total of direct solar radiation and diffuse sky radiation received
by a horizontal surface. Global radiation is measured by
pyranometers.
Gust The peak momentary wind velocity within a given interval of time,
for example, 10 minutes.
Hexadecimal Numbering system using the base number 16 and including the ten
decimal digits (0 to 9) along with six alpha digits (A to F).
Humidity The water vapor content of the air. Weather station sensors commonly
measure relative humidity. Relative humidity is the ratio of water
vapor pressure present in a gas to the maximum pressure of water
vapor that could be present in the gas in that temperature.
LED Light-Emitting Diode
Logger The processing unit of the system. The electronics of the QML logger
take care of measuring, storing, and processing of the measured
parameters.
Logging The process of storing the measured and calculated values in the
logger's memory.
Lull The minimum of wind speed during a certain time interval.