NovaLynx Corporation
260-RGAI-70
Page 7
May 2022
7
OPERATION
7.1
Ramp Mode
Once the wiring has been completed and power applied to the system, the output of the 260-RGAI-70
will be 4 mA, indicating no rainfall. Each time the bucket in the rain gauge tips, the output will increase
by 0.16 mA. When the maximum value is reached (20 mA), the next tip will return the output to 4 mA.
The output holds at the value reached when the last tip is detected, unless the power to the loop
circuit is interrupted. Therefore, if it is desirable to reset the output to 4 mA (indicating no rain), simply
interrupt the power to the unit.
The monitoring equipment may need to be programmed to output the amount of rain in inches or
millimeters to make the information understandable. Each rain gauge has a calibration factor
expressed as inches or millimeters per tip. To calculate the full scale range, multiply the calibration
factor by 100.
Example:
260-2501 Rain Gauge with a calibration factor of 0.01"/tip.
Full Scale Range = 0.01"/tip x 100 tips = 1 inch = 20 mA
7.2
Rain Detector Mode
After the wiring has been completed and power applied to the system, the output of the 260-RGAI-70
will be 4 mA, indicating no rainfall. When rain is detected (i.e. the bucket tips) the output goes to
20 mA and a timer begins to count down. If more tips are detected before the timer expires, the timer
resets and begins to count down. This continues until the last tip is detected, and the timer finally
expires, causing the output to return to 4 mA. The duration of the timer is set by the mode select
switch, as discussed in the previous section.
7.3
Mode Comparison Graphs
RAIN DETECTION MODE OUTPUT SIGNAL
16
TIME
4
8
12
20
m
A
}
T
IP
S
R
E
S
E
T
P
E
R
IO
D
}
}
16
TIME
4
8
12
20
m
A
0.5"
1.0"
0.0"
RAMP MODE OUTPUT SIGNAL
DWG 890-0125-01
