Connecting pyranometer to WXT536 - WXT530

WXT530 Series User Guide

Document code
M211840EN
Revision
F
Language
English (United States)
Product
WXT530
Document type
User guide
The transmitter radiation shield reflects light. If you install the transmitter next to a pyranometer, the pyranometer can give incorrect measurements. Install the transmitter on the same level with the pyranometer so that the distance between the units is approximately 80 cm (31.5 in).
Table 1. Pyranometer connections
Solar radiation connections Pyranometer
Pin Pin function Function
1 - -
2 - -
3 - -
4 - -
5 - -
6 SR+

Solar radiation sensor input +

0 ... 25 mV

Positive
7 SR-

Solar radiation sensor input -

Negative
8 - -

After wiring the sensor and connecting it to WXT536, you can configure the analog input through Vaisala Configuration Tool.

To open the configuration window, select Settings > Analog inputs.

Figure 1. Solar radiation sensor setting in configuration tool

Average annual solar radiation arriving at the top of the Earth's atmosphere is roughly 1361 W/m2. The sun's rays are attenuated as they pass through the atmosphere, leaving maximum normal surface irradiance at approximately 1000 W/m2 at sea level on a clear day.

Typical measurement range of the solar sensor is approximately 0 … 2000 W/m2 but every sensor has a different sensitivity value. If the solar sensor sensitivity value is 5 µV/W/m2, the solar radiation gain is:
Solar radiation gain = 1 µV / 5µv/W/m2 = 200 000 W/m2

In Solar radiation gain, type 200 000 and select OK.

In above example the WXT536 limits the maximum solar measurement output to 25 mV / 5 µv/W/m2 = 5000 W/m2, which is well sufficient in normal outdoor use.