Campbell Scientific CR1000 Manuel D'utilisation page 238

Chapitre 8. Instructions mathématiques de calculs
TimeIntoInterval (TintoInt, Interval, Units)
VaporPressure (Dest, Temp, RH)
8-32
L'instruction TimeIntoInterval (ou IfTime) est utilisée pour donner un niveau
logique vrai ou faux base sur l'horloge temps réel de la centrale de mesure.
Syntax
Variable = TimeIntoInterval( TintoInt, Interval, Units )
ou
If TimeIntoInterval ( TintoInt, Interval, Units )
Remarks
When encountered by the datalogger program, the TimeIntoInterval statement is
evaluated True (-1) or False (0) based on the datalogger's real-time clock. Time is
kept internally by the datalogger as the elapsed time since January 1, 1990, at
00:00:00 hours. When the Interval divides evenly into this elapsed time, the
TimeIntoInterval is set True. The TimeIntoInterval instruction can be used to set
the value of a variable to -1 or 0 (first syntax example), or it can be used as an
expression for a Condition (second syntax example).
The TimeIntoInterval instruction has the following parts:
TintoInt The TintoInt, or time into interval, argument allows the programmer to
define an offset from the Interval at which the TimeIntoInterval statement will be
evaluated true. For example, if the Interval is set at 60 minutes, and TintoInt is set
to 5, TimeIntoInterval will be True at 5 minutes into the hour, every hour, based on
the datalogger's real-time clock. If the TintoInt is set to 0, the TimeIntoInterval
statement is True at the top of the hour.
Interval The Interval is how frequently the TimeIntoInterval statement will be
evaluated True, based on the datalogger's real-time clock.
Units The Units argument is used to specify the units on which the TintoInt and
Interval arguments will be based. The options are microseconds, milliseconds,
seconds, minutes, hours, or days.
Notes:
TimeIntoInterval must be placed within a scan to function.
This instruction is also known as IfTime. Either keyword can be used within the program.
L'instruction VaporPressure calcule la pression de vapeur ambiante (Vp) à partir
des valeurs mesurées auparavant de la température et de HR (humidité).
L'instruction calcule d'abord la pression de vapeur saturée de la température de
Lowe (voir l'instruction SatVp). Ensuite la pression de vapeur est calculée en
multipliant la fraction HR :
Vp = SatVp x RH/100