EKO INSTRUMENTS CO., LTD. Sunshine Duration Meter MS-093 Instruction Manual Ver.4
Pg. 14
5-4. Measurement/Operations
1. Measurement
Sunshine duration is defined as there is a count of sunshine duration when there is irradiance of more than
120W/m
2
in DNI (Direct Normal Incidence). MS-093 takes samplings for 36 seconds to take the sunshine
duration measurement. Therefore, when maximum of 100 times of sunshine duration signals are counted
within 1 hour, the result of sunshine duration will be 1 hour; when 50 times of sunshine duration signals are
counted within 1 hour, the result of sunshine duration will be 0.5 hours.
The sunshine duration signals from MS-093 uses non-voltage contact signal, and it makes the contact for 1
second when sunshine is detected. When taking measurement by connecting to a data logger, MS-093
cannot be connected to an analog voltage input channel, thus it needs to be connected to a channel which
can measure non-voltage contact pulse input.
2. Operation
When the MS-093 is connected with power, the mirror starts to rotate.
Mirror rotates once by the 36 seconds cycle. When the mirror faces in the direction of the sun, the
pyroelectric sensor responds; however, it does not output the sunshine duration output pulse at that moment.
The pulse contact is made at the last one second of the 36 seconds cycle from the power is turned on.
In case of there is no sunshine, the sunshine duration output contact remains in break condition.
