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Apogee Instruments’ silicon-cell pyranometers feature a silicon-cell detector. The sensors are accurate, stable, durable, and cost-effective, the results of continual refinement of design.


Accurate, Stable Measurements
Calibration in controlled laboratory conditions is traceable to the World Radiometric Reference in Davos, Switzerland. Pyranometers are cosine-corrected with directional errors less than ± 5 % at a solar zenith angle of 75°. Long-term non-stability determined from multiple replicate pyranometers in accelerated aging tests and field conditions is less than 2 % per year.


Rugged, Self-cleaning Housing
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.


Heated Option
A heated pyranometer (SP-230 All-season) is available with a 0.2 W heater to keep water (liquid and frozen) off the sensor and minimize errors caused by dew, frost, rain, or snow blocking the optical path.


Output Options
Multiple analog output options are available including: 0 to 350 mV, 0 to 2.5 V, 0 to 5.0 V, and 4 to 20 mA 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.

Typical Applications
Applications include shortwave radiation measurement in agricultural, ecological, and hydrological weather networks. Sensors are also used to optimize photovoltaic systems.

The AM-110 mounting bracket facilitates mounting the AL-100 leveling plate to a mast or pipe. The bubble-level in the plate makes leveling simple and accurate.


Warranty and Support
All Apogee products are backed by an industry-leading four year warranty and outstanding customer support.


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 >


Irrigation Study

Irrigation Study
Pyranometer mounted on model train to collect measurements in orchard for irrigation study.
Read More >

View all Case Studies >


Need help choosing a sensor?

  Technical Information
Technical Information
Find knowledge base 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 highter 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) 360 to 1120 nm 385 to 2105 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.

+ Which pyranometer do I need to monitor my solar panels?
For information on using Apogee pyranometers to monitor solar panels, please visit https://www.apogeeinstruments.com/solar-energy-pv-monitoring/.
+ Can I use my pyranometer under water?
Absolutely. We have quite a few customers that purchase our sensors for continuous deployment in underwater applications such as marine biology and hydrology. The SP-series pyranometer sensors are completely sealed and watertight and the cable can be submerged underwater as well.
Caution: The MP-series handheld meters cannot be submerged (the screen is splash resistant). The sensor head and cable of the MP-200 can be submerged.
+ Do I need to order a sensor to go with my meter?
No. All Apogee meters (MO, MP, MQ, and MU series) either have sensors built into the meter or attached via two meters of cable. If you order a sensor only (SI, SO, SP, SQ, and SU series) you will need to have your own datalogger (or, depending on the sensor, a voltmeter) to collect information form the sensor.

spec sheets
Specification Sheets



How to Choose the Right Pyranometer

Lecture 3-Shortwave Radiation and Pyranometers

Silicon-cell Pyranometers

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

Pyranometer User's Guide

SP-230 Heated Pyranometer Time Lapse

Apogee Instruments Meter User Guide