®
SECTION 5 WEATHER
making
since 1986
water work
E. ET
The ET section of the controller can be programmed
to use evapotransperation data accessed from an
ET Gage, or controller pre-set values, to compute
irrigation run times using the following:
•
Irrigate using ET table
•
Irrigate using ET averaging
•
Adjust allowable percentage of historical ET
•
Use of crop coefficients
From the WEATHER SETUP screen (Figure 5.2).
1.
Press the
ET
Menu key.
The DAILY ET SETUP screen is displayed
(Figure 5.21).
PROG A: NO ---
PROG E: NO ---
DAILY ET SETUP ( 8:00PM TO 8:00PM )
(…………………………….)
ET TABLE ET AVERAGING
IRRIGATE USING USE
PROG B: NO ---
PROG D: NO ---
PROG C: NO ---
DRIP 1: NO ---
DRIP 2: NO ---
Figure 5.21
Note:
The text line directly under the heading bar
will have each program tag if you are currently using
them. (See Section 3 Start Times & Water Days /
Name:). If you do not have any selected the default
(………………………..) will appear.
1. Irrigate using ET table
A NO next to a program indicates the program is
using minutes. Once YES is selected for a program,
any station assigned to that program will now use
daily ET to automatically adjust the amount of time
the station will run during it’s next irrigation.
1.
Press the
PLUS
or
MINUS
keys to
change the setting.
Note:
If the setting is changed to YES for a program,
the USE ET AVERAGING setting will automatically
change to YES for that particular program.
2.
Press the
PLUS
or
MINUS
keys to change the setting.
2. Use ET averaging
A YES next to a program indicates ET averaging is
enabled for that program, which is only available if
the program is in daily-ET mode. With ET averaging
ON the controller will not use a single ET valve to
calculate the next run times. Instead it will use the
average of the last 7 days of ET (Figure 5.22).
PROG A: YES YES
Crop Coefficients
DRIP 1: NO ---
DRIP 2: NO ---
Allowable % of Historical ET: 150%
PROG E: NO ---
DAILY ET SETUP
ET TABLE ET AVERAGING
IRRIGATE USING USE
PROG B: NO ---
PROG D: NO ---
PROG C: NO ---
Figure 5.22
3. Allowable % of historical ET
This setting controls the maximum allowable
amount of ET that can be used to calculate station
run times. The default is 150%, which means that if
real-time ET measured by the gage, exceeds 150%
of historical ET, the controller will place an ET value
in the ET table equal to 150% of historical ET
instead of the actual real-time ET. This setting allows
the user to control the maximum amount of total
irrigation time for sites that have a limited water
window (Figure 5.23).
Note:
The water window is the time from when you
can start irrigating to when you have to end
irrigation.
PROG A: YES YES
Allowable % of Historical ET: 150%
Crop Coefficients
DRIP 1: NO ---
DRIP 2: NO ---
PROG E: NO ---
DAILY ET SETUP
ET TABLE ET AVERAGING
IRRIGATE USING USE
PROG B: NO ---
PROG D: NO ---
PROG C: NO ---
Figure 5.23
