The SMP22 is a secondard standard pyranometer that combines the sensor technology of the CMP22 with the added benefits of the both a RS485 Modbus interface and a standardised analogue output. The SMP22 uses a 32-junction thermopile sensing element under two very high quality quartz domes, which allows for a wider spectral range, improved directional error and reduced thermal isolation. The housing include a screw-in drying cartridge that can simply be removed using a coin. This allows the desiccant to be replaced on site without the need for specialist equipment. Convenient desiccant refill packets are available to make this process as simple as possible.

The housing design of the SMP 22 is designed with a internal temperature sensor to monitor the housing temperature and the SMP 22 uses a passive temperature compensation circuit with a standardised linear function to allow for individual temperature compensation. Each instrument is supplied with its own individual temperature and directional response data for improved post processing of recorded data. This individualised data along with the high quality quartz domes allows the SMP22 to be the most accurate pyranometer currently available on the market. The addition of the RS485 communications allows for units to be configured for identical outputs allowing units to be quickly swapped out for any maintenance or other calibration procedures. Providing a near seemless transfer, meaning no loss of data as units are swapped and any connected equipment is adjusted for the new sensors sensitivity.

The SMP22 come with options of either a 0-1V or 4-20mA analogue output and these can be easily rescaled by the user with the supplied PC software. The units are configured with the 0-1V output set as -200 to 2,000Wm² and the 4-20mA output as a 0-1,600Wm². Negative ranges can be used to allow the sensor to show levels at night when there is heat emitted from the sensor. All SMP's have the RS485 Modbus RTU interface, very low power requirements and are supplied with comprehensive, traceable, calibration certificates. Calibrations are traceable to the World Radiometric Reference (WRR) in Davos Switzerland and are performed in accordance with ISO 9847, Annex A.3 'Calibration of Field Pyranometers by comparison to a Reference Pyranometer'.

 Diagram

Specification

SMP22 instruments have an 8-pin socket and can be connected to a standard cable with a pre-wired waterproof 8 pin plug and flying leads. Cable lengths of 10m, 25m, 50m and 100m are available.