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Apogee Instruments offers cost-effective silicon-cell pyranometers, thermopile pyranometers, and aspirated radiation shields used to monitor solar energy resources, optimize panel placement for maximum efficiency, monitor photovoltaic system performance, and determine site location.

Silicon-cell Pyranometers

Apogee silicon-cell pyranometers feature a monocrystalline silicon-cell detector that has the same spectral response as a PV module. The sensors quantify shortwave radiation being harnessed as electricity. 

Same Characteristics as a
PV Module

Apogee silicon-cell pyranometers feature a monocrystalline silicon-cell detector that has the same spectral response as a PV module.


Accurate and Stable Measurements
Pyranometers provide accurate readings at low-sun angles. They are cosine-corrected with directional errors less than ± 5 % at a solar zenith angle of 75°. Calibration in controlled laboratory conditions is traceable to the World Radiometric Reference in Davos, Switzerland. 


Rugged, Self-cleaning Head
Patented domed shaped sensor head (diffuser and body) facilitate runoff of dew and rain to keep the diffuser clean and minimize errors caused by dust blocking the radiation path. Sensors are housed in a rugged anodize aluminum body and electronics are fully potted.


Output Options
Multiple analog output options are available including: 4 to 20 mA, 0 to 2.5 V, 0 to 5.0 V, and 0 to 350 mV ranges. The silicon-cell pyranometer is also available attached to a hand-held meter with digital readout, and as a digital 'smart' sensor that uses USB communication and custom software to interface directly to a computer.


Sensor features a compact design allowing it to be integrated easily with any application. The AL-100 bubble-level can be used with the AM-110 solar sensor mounting bracket to mount the sensor for global horizontal measurements.


Apogee silicon-cell pyranometers are used to monitor solar energy resources, optimize panel placement for maximum efficiency, monitor system performance, and determine site location.

Case Studies

SP-230 Project Loon

Google's Project Loon
Apogee's SP-230 heated pyranometer was selected to monitor PV panels on Project Loon.
Read More >


Monitoring PV Panels on Jin Peop Library

Monitoring PV Panels on Jin Jeop Library
SP-110's are integrated as part of a PV monitoring system for a PV power generation facility on the roof of the Jin Jeop library in Korea.
Read More >


Solar Power Plants on Lakes and Dams

Solar Power Plants on Lakes and Dams
Studying solar radiation at different angles to determine locations for solar power plants.
Read More >

View all Case Studies >


Thermopile Pyranometers
Apogee thermopile pyranometers are cost-effect and feature a blackbody thermopile detector that provides a broader and more uniform spectral response for better performance in all atmospheric conditions, particularly under cloudy conditions. For more information on thermopile pyranometers, click here. >
Fan-aspirated Radiation Shield
Did you know that traditional multi-plate radiation shields cause ambient air temperature measurement errors up to 10 C in high solar, low wind conditions? With many performance monitoring standards calling for a measurement uncertainty of less than 1 C, this is a large and frequently overlooked problem. The TS-100 is the solution. The unique shape and ultra-low-power fan ensure an uncertainty of only 0.2 C in all conditions. For more information on the TS-100, click here. >



Silicon-cell Pyranometers


Apogee SP-510 Thermopile Pyranometer Introduction


Connecting an Apogee SP-214 Pyranometer to an SMA Cluster Controller

+ More Videos


Pyranometer User's Guide

Solar Radiation Shield Overview

Aspirated Radiation Shield
Need help choosing a sensor?

  Technical Information
Technical Information
Find software, articles, manuals, FAQs, technical support, and more.
+ What type of Apogee pyranometer do I need?
Apogee offers silicon-cell and thermopile detector pyranometers. From a big picture perspective, the thermopile pyranometer is more accurate in all conditions than the silicon-cell models.

Generally speaking, thermopile pyranometers have a larger spectral range (this makes them more accurate in all atmospheric conditions), smaller output signal, longer response time, and are more expensive than silicon-cell detectors.

Silicon-cell pyranometers are less expensive and faster response, but errors are higher under cloudy conditions. The table below is a comparison of the general specifications for Apogee silicon-cell pyranometers and thermopile pyranometers:

Specifications Silicon-cell Detector Thermopile Detector
Calibration Uncertainty ± 5 % ± 5 %
Cosine Response ± 5 % below 75° zenith angle Less than 30 W m-2 at 80° zenith angle
Error Due to Clouds + 10 to 15 % (common to all silicon-cell pyranometer) ± 2 %
Spectral Range (50% Points) 350 to 1120 nm 380 to 2150 nm
Base Model Output Voltage 0 to 350 mV = 0 to 1750 W m-2 0 to 114 mV = 0 to 2000 W m-2
Response Time Less than 1 ms 0.5 seconds
+ Which Silicon-cell Pyranometer model do I need?

All SP-100, SP-200, and MP series silicon-cell pyranometers use the same silicon-cell detector. The model number you need depends on which output is compatible with your datalogger. Model numbers are listed below with their output:

SP-110: 0 to 350 mV = 0 to 1750 W m-2

SP-230: 0 to 250 mV w/Heater = 0 to 1750 W m-2
*Note: The SP-230 has the same voltage output as the SP-110 but features a built in heater and Delran mounting stand for deployment in condensing or cold weather applications (e.g. frost, snow, sleet, freezing rain).

SP-212: 0 to 2.5 V = 0 to 1250 W m-2

SP-215: 0 to 5.0 V = 0 to 1250 W m-2

SP-214: 4 to 20 mA = 0 to 1250 W m-2 *Best model for most solar inverters.

SP-420: USB/software

MP-100: Sensor integrated into the top of the handheld meter with digital readout

MP-200: Sensor attached to a handheld meter with digital readout

*The above ranges are standard and built to stock. If you need a larger range than what is listed please contact technical support for a quote on your specific requirement.

+ How do I connect Apogee's pyranometer to an SMA cluster controller?
A video on how to connect an Apogee SP-214 (4-20 mA) Pyranometer to an SMA cluster controller can be found here.
+ What sensors will the fan-aspirated radiation shield accommodate?
The shield's sensor port is designed to easily accommodate combinations of thermistors, PRTs, and humidity probes by using one of our sensor port adaptor plugs. We currently stock port adaptors for Apogee models: ST-110 precision thermistor and Apogee ST-300 PRT, Campbell Scientific model CS215, Vaisala models: HMP110, HMP60, and HMP155, and Rotronic model HC2-S3. If you use a different probe, please contact us to discuss compatibility with a custom port adaptor. To view a technical drawing of sensor port adaptor options click here.

spec sheets
Specification Sheets




For complete selections, visit Silicon-cell Pyranometers, Thermopile Pyranometers, and Fan-aspirated Radiation Shield