Silicon Irradiance Sensors:
1. Why should I use a Silicon Irradiance Sensor instead of a pyranometer to monitor irradiance levels at my solar array?
a. Because a Silicon Irradiance Sensor is made of the same material as your array and is mounted in the same “plane” as the array, it will give a much more accurate reading of solar irradiance levels reaching your solar modules, considering all factors such as angle of incidence, reflected light, etc. A pyranometer, particularly one mounted simply in a horizontal plane, is going to give a reading of all absorbed irradiance, including that reflected from nearby surfaces.
2. How long has IMT SOLAR been manufacturing Silicon Irradiance Sensors?
a. Our partners in Germany, IMT GmbH, have been designing and manufacturing Silicon Irradiance Sensors since 1993. Because of our experience and a well thought out design process there are tens of thousands of our sensors installed around the world – including many from the earliest days of manufacturing.
3. What is the IP rating of our Silicon Irradiance Sensors?
a. The traditional style sensor (SI- Standard) has an overall rating of IP65 with a cable gland rating of IP67.
4. What is the best mounting position for the silicon irradiance sensors?
a. The sensors should be mounted at the same tilt angle as the array (same “plane” as the array.)
5. The temperature output signal on the Si-I-420TC-T (4-20mA) sensor is listed on the data sheet as 0.1231*T(°C)+8.9231=I(mA). What exactly does this scale to at my 4-20mA analog input channel?
a. The scaling range is -40°C to +90°C (i.e. 4mA = -40°C and 20mA = +90°C).
6. The temperature output signal on the Si-V-10TC-T (0-10VDC) sensor is listed on the data sheet as 0.0769*T(°C)+3.0769=U(V). What exactly does this scale to at my 0-10V analog input channel?
a. The scaling range is -40°C to +90°C (i.e. 0V = -40°C and 10V = +90°C).
7. The IMT digital silicon irradiance sensor has an output that is RS485 communications. Does this RS485 channel include a Modbus protocol as an option?
a. Yes! We introduced the embedded Modbus RTU protocol in the summer of 2010 and this digital sensor has quickly become one of our most popular models.
8. What is the color coding on the IMT analog irradiance sensors with the cable pre-installed?
Irradiance: Orange
Power Supply (Plus): Red
Power Supply / Signal (Minus): Black
Temperature: Brown; only versions with „-T“
Shield: Black (bigger diameter)
9. What is the color coding on the IMT digital RS485 irradiance sensors with the cable pre-installed?
Data Minus: Orange
Data Plus: Brown
Power Supply Plus: Red
Power Supply Minus: Black
Shield: Black (bigger diameter)