Kipp and Zonen SMP10 and SMP11. What’s the difference?

ESS Earth Sciences are frequently asked what is the difference between the SMP10 pyranometer and SMP11 pyranometer? We will save you some time so you don’t have to read all of this article; there is virtually no difference in terms of accuracy and sensitivity between the two versions. The acquired data will be the same. However, there is one big difference, if you are still interested please read on.

The similarities.

The similarities between the SMP10 and the SMP11 are best shown using numbers. Below you will see the performance specifications of the two versions of the pyranometer. Notice that the specification of the SMP10 and SMP11 are identical.

Skip this table if you want to get straight to the differences.

SPECIFICATIONSMP10SMP11
Classification to ISO 9060:1990Class A (Secondary Standard)Class A (Secondary Standard)
Analogue output • V-version0 to 1V0 to 1V
Analogue output range* -200 to 2000W/m -200 to 2000W/m²
Analogue output • A-version4 to 20mA4 to 20mA
Analogue output range*0 to 1600W/m² 0 to 1600W/m²
Serial outputRS-485 Modbus®RS-485 Modbus®
Serial output range -400 to 4000W/m² -400 to 4000W/m²
Response time (63%)< 0.7 s< 0.7 s
Response time (95%)< 2 s< 2 s
Spectral range (20 % points)270 to 3000nm270 to 3000nm
Spectral range (50% points)285 to 2800nm285 to 2800nm
Zero offsets (unventilated)  
(a) thermal radiation (at 200 W/m²)< 7 W/m²< 7 W/m²
(b) temperature change (5 K/h)< 2 W/m²< 2 W/m²
Non-stability (change/year)< 0.5%< 0.5%
Non-linearity (100 to 1000W/m²)< 0.2%< 0.2%
Directional response
(up to 80 ° with 1000W/m² beam)
< 10 W/m²< 10 W/m²
Temperature response< 1% (-20°C to +50 °C)
< 2% (-40 °C to +70 °C)
< 1% (-20°C to +50 °C)
< 2% (-40 °C to +70 °C)
Spectral selectivity (350 to 1500nm)< 1%< 1%
Tilt response (0 ° to 90 ° at 1000W/m²)< 0.2%< 0.2%
Field of view180 °180 °
Accuracy of bubble level< 0.1 °< 0.1 °
Power consumption (at 12 VDC)V-version: 55mWV-version: 55mW
A-version: 100mWA-version: 100mW
Software, Windows™Smart Sensor Explorer Software,
for configuration, test and data logging
Smart Sensor Explorer Software,
for configuration, test and data logging
Supply voltage5 to 30VDC5 to 30VDC
Detector typeThermopileThermopile
Operating and storage temperature range-40 °C to +80 °C-40 °C to +80 °C
Humidity range0 to 100%0 to 100%
MTBF (Mean Time Between Failures) **> 10 years> 10 years
Ingress Protection (IP) rating6767
Onsite pyranometer uncertaintyCalculate with Suncertainty AppCalculate with Suncertainty App
Recommended applicationsHigh performance for PV panel and
thermal collector testing, solar energy
research, solar prospecting, materials
testing, advanced meteorology and
climate networks
High performance for PV panel and
thermal collector testing, solar energy
research, solar prospecting, materials
testing, advanced meteorology and
climate networks

SMP10 Pyranometer and SMP11 Pyranometer – The Differences

There is only one difference between the SMP10 pyranometer and SMP11 pyranometer, which is the location of the moisture-absorbing material (desiccant). In the SMP10, the desiccant is located and sealed within the body. Whereas, in the SMP11, the desiccant is in a drying cartridge screwed into the outside.

If you look at the photos below you will notice that the SMP11 (on the left) has a see-through cartridge protruding with yellow desiccant in. However,m this is not on the SMP10. The same applies to the analogue only CMP10 CMP11 pyranometers from Kipp and Zonen.

As a result of the SMP10’s desiccant being held within the body of the pyranometer, there is a near-total elimination of ‘access’ points for moisture to ingress. Subsequently, the SMP10’s internal drying cartridge only requires changing after 10 years. As standard, it is changed every time it is sent to the manufacturer for re-calibration (should be performed every 1-5 years).

SMP10 Pyranometer from Kipp and Zonen. Note the external drying cartridge.
SMP11 Pyranometer from Kipp and Zonen. no sun shield. Note the external drying cartridge on the left.
SMP10 CMP10 Pyranometer from Kipp and Zonen. No external drying cartridge.
SMP10 Pyranometer with no sun shield. Note the lack of an external drying cartridge.

For the SMP11 it is crucial that the drying cartridge be inspected every month to check for decolouration of the desiccant which indicates it is reaching saturation from absorbing moisture. Though in less humid areas this can be extended to a longer period of time.

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