Ask Us
WET Labs

PAR Photosynthetically Active Radiation Sensor

Provides superior data along with high quality construction to stand up even in the harshest conditions.

Sea-Bird Scientific's series of Photosynthetically Active Radiation (PAR) sensors provide highly accurate measurements of PAR (400 - 700 nm) for a wide range of aquatic and terrestrial applications.  From limnologists and oceanographers to plant and crop physiologists, scientists trust our PAR sensors to provide superior data quality and rugged construction to withstand harsh field conditions.

Sea-Bird Scientific's PAR sensors measure quantum irradiance with near flat spectral response and cosine spatial response. Cosine collectors for in air and in water measurements, housings for two depth ratings, 1000m and 7000m, and digital and analog data output options, support integration of the PAR sensor in instrument packages for a range of deployment conditions.

The analog voltage signal output options enable the PAR sensor to be integrated with Sea-Bird Scientific CTD platforms and other terrestrial scientific data loggers with analog signal inputs.  The logarithmic scale option is used for integration with CTDs for profiling applications; for example, where higher signal resolution is required at low light levels.  The linear scale option is suited for high light conditions such as in air.

The PAR sensor serial data option provides high resolution data over the entire dynamic range, and overcomes the challenges associated with degradation of an analog signal over long cables. The serial instrument can be integrated with CTDs or other data loggers that have serial data input channels, or directly to a computer using the optional USB cable.

In addition, the serial PAR sensor provides tilt and internal temperature measurements that can be used for data quality analysis, and user programmable analog voltage signal output, with selectable ranges on either linear or logarithmic scales.  The analog signal is transmitted simultaneously with the serial output and enables custom scaling of the analog signal for specific deployment conditions.



Spectrum 400 - 700 nm
PAR Range 0 – 5000 μmol photons m -2s -1
Spatial cosine response
Cosine error 0° – 60°  <3%
60° – 85° <10%
Collector area 86 mm2
Detector 17 mm2 silicon photo diode


Input Voltage 6 – 28 VDC
Current Draw 17 mA @ 12 VDC
Connector Subconn MCBH4M or MCBH8M (serial)
Auxiliary Sensors Integrated temperature and tilt for serial option


Sample Rate 100 Hz maximum
Digital Output RS-232 ASCII, up to 100 Hz
Analog Signal Output 0.125 - 4.0 V
Analog Signal Scaling linear or logarithmic


Weight (in air) 88.0 g (plastic) or 182 g (titanium)
Weight (in water) 39.0 g (plastic) or 133 g (titanium)
Depth Rating 1000 m (plastic) or 7000 m (titanium)
Length 139 mm (with connector) 89 mm (housing)
Diameter 25 mm


The list below includes (as applicable) the current product brochure, manual, and quick guide; software manual(s); and application notes.

Title Type Publication Date PDF File
PAR Datasheet Product Datasheet Friday, June 23, 2017 datasheet_PAR.pdf
HyperOCR Hyperspectral Radiometer Datasheet Product Datasheet Friday, June 23, 2017 datasheet_PAR.pdf
ECO-PARS Drawing Product Drawing Tuesday, July 4, 2017 drawing-ECO-PARS.PDF
ECO PARB Drawing Product Drawing Tuesday, July 4, 2017 drawing-ECO-PARB.PDF
User’s Manual PAR Sensor - Logarithmic Analog Product Manual Thursday, June 22, 2017 Manual-PAR-LOG-SAT-DN-00636.pdf
User’s Manual PAR Sensor - Linear Analog Product Manual Thursday, June 22, 2017 Manual-PAR-LIN-SAT-DN-00637.pdf
User’s Manual PAR Sensor - Serial Product Manual Thursday, June 22, 2017 Manual-PAR-SER-User-SAT-DN-00633.pdf
SatView Manual Software Manual Wednesday, June 14, 2017 SatView-Manual.pdf
SatCon Manual Software Manual Wednesday, March 9, 2011 SatCon-Manual.pdf
AN96: Using Sea-Bird Scientific (Satlantic) PAR Light Sensors Application Notes Wednesday, July 26, 2017 appnote96Jul17.pdf

SatView is a real-time interactive data logging and display application for use with Sea-Bird radiometers. SatView makes it easy to connect to your Satlantic instruments and view time series, spectral plots, and depth profiles while capturing data for subsequent conversion and post-processing.

SatView features include:

Version 2.9.5 released April 11, 2014

SatView 2.9 provides Windows 7 compatibility, improved PAR sensor support, wavelength range settings for spectral views, additional cast card fields for post-processing, support for up to 96 serial ports, GPS data validation and many more. Please refer to the release notes for a detailed list of recent improvements.

SatView-2.9.5-b7-x86.exe for Windows 7/8/10

SatCon is a software utility for converting raw binary data, as logged by SatView, into readable ASCII text suitable for import by third party applications such as spreadsheets or databases. Data can be extracted in calibrated physical units or raw binary counts. SatCon can be operated interactively through a user friendly graphical interface, or in batch mode as a background process.

For minimum system requirements, installation instructions, and new features, please refer to the release notes in the SatCon User Manual.

Version 1.5.5 released April 28, 2011
SatCon-1.5.5-b2-x86.exe for Windows 7/8/10

What are SIP files?

Files that are delivered with Sea-Bird Scientific and third party equipment to describe the sensors data output and calibration coefficients come in two types. Calibration files or *.cal files and telemetry definition format files or *.tdf files. In some cases, systems are created that network many sensors together and their combined data is provided in one serial output. The simplest example is a HOCR sensor that generates both light and dark frames. A more complex example is a HPROII profiling system that may contain as many as 5 sensors and 7 individual calibration and tdf files. These files must be used to both collect and process the data. This can become quite confusing to keep track of all these files so Sea-Bird Scientific developed SIP files. All CAL and TDF files required for a system are zipped using winzip and the extension changed from *.ZIP to *.SIP. The file name includes the system description (usually the network master serial number) and the creation date. This SIP file can then be used in place of individual files to collect and process data.

Bioshutter II

The Bioshutter II is an autonomous underwater shutter attachment designed for use with Satlantic radiometers. The primary purpose of the shutter is to prevent marine bio-fouling of the sensor optics in moored, time-series application. Copper, and copper-based alloys have long been known to have good resistance against bio fouling and have been used in a diverse variety of commercial applications. Scientists working at the University of California Santa Barbara Ocean Physics Lab under the auspices of the National Ocean Partnership Programs' (NOPP) Ocean System of Chemical, Optical, and Physical Experiments (O-SCOPE) project developed an underwater shutter device for use with instruments such as Satlantic's OCR-500 and HyperOCR series instruments. The Satlantic Bioshutter II device builds upon the success of this instrument by combining an innovative copper shutter and an input power controlled motor drive assembly to ensure robust operation in harsh marine environments.