DAVIS Energy EnviroMonitor: Console - Manual (Page 18)

Period
Energy EnviroMonitor Manual Page 11
Dew-Point
Dew-point is the temperature to which air must be cooled for saturation (100%
relative humidity) to occur, providing there is no change in water content. The
dew-point is an important measurement used to predict the formation of dew,
frost, and fog. If dew-point and temperature are close together in the late after-
noon when the air begins to turn colder, fog is likely during the night. Dew-
point is also a good indicator of the air’s actual water vapor content (as
opposed to relative humidity). High dew-point indicates high vapor content;
low dew-point indicates low vapor content. You can even use dew-point to
predict the minimum overnight temperature. Provided no new fronts are
expected overnight, the afternoon’s dew-point gives you an idea of what mini-
mum temperature to expect that night, since the air is not likely to get colder
than the dew-point anytime during the night.
• Current Dew-Point (Alarm: when temperature is within 2˚F of dew-point)
Time
The GroWeather has a clock and a calendar for tracking time and date. The cal-
endar automatically adjusts during leap years, providing you enter the current
year (see “Entering Time, Date, or Year” on page 42) when you apply power to
the unit.
• Current Time (Alarm: standard)
• Current Date
• Current Year
• AutoClear Time Setting
• Period Information
P ERIOD
The Energy EM uses a single time period for all values which accumulate totals
or calculate daily averages over an interval. Beginning a new period clears all
data from the previous period. The system stores the beginning date of the
period, which you may display along with the number of days which have
elapsed since the beginning of the period.
Note: The system records the start time of the period to the nearest 90 minutes. Therefore, all average val-
ues are exact to the nearest 90-minute mark throughout the period. However, averages calculated
during the period are most accurate when the period length is an exact number of days (that is, if
you display the average at the same time of day at which the period started). When the length of the
period is displayed, the Energy EM rounds down to the nearest whole day COMPLETED.
The following values are accumulated or averages calculated during the
period. Note that averages are not displayed (i.e., a series of dashes appears
instead) until at least one day has elapsed.
• Total Cooling Degree-Days