Go Direct® PAR (Photosynthetically Active Radiation)

The Go Direct PAR Sensor reports the Photosynthetic Photon Flux Density (PPFD), which corresponds to micromoles of photons per meter squared per second (μmol m^-2 s^-1). This is the power of electromagnetic radiation in the spectral range that is used by plants for photosynthesis. It features a waterproof sensor head and can be used to measure PPFD from sunlight and electric light sources. This sensor is ideal for experiments investigating photosynthesis and primary productivity and can be used in many agricultural and environmental science applications.

Remote Data Logging—Go Beyond Wireless Limits!

This Go Direct sensor is capable of remote data logging! This feature allows sensors to store data directly to their internal memory—ideal for investigations that extend beyond typical connection ranges like long-term environmental monitoring or rocket launches. It works seamlessly with our award-winning Vernier Graphical Analysis^® app so students can visualize their data and make key connections between abstract science concepts and real-world phenomena. Learn more about remote data logging.

Rechargeable Battery—Ready When You Are

The robust rechargeable battery offers long battery life and provides always-ready operation when using the sensor wirelessly. Monitor battery life directly from our award-winning Vernier Graphical Analysis^® app, as well as LabQuest^® 3. Should the battery run low, simply connect the sensor to the charging cable and keep on collecting—no interruptions or inconvenience to you or your students.

Wireless or Wired—The Flexibility to Choose

Our Go Direct sensors connect directly to your mobile device, Chromebook^™, or computer using our Vernier Graphical Analysis^® app—no additional equipment or software purchases are necessary. Go Direct sensors can be used wired via USB or wirelessly via Bluetooth^® wireless technology, allowing you to choose the best solution for your classroom or laboratory.

Specifications

PAR Range: 0 to 2500 μmol m^-2 s^-1PPFD) in full sun
Absolute Accuracy: ±5%
Repeatability: ±1%
Long-Term Drift: Less than 2% per year
Cosine Response:
- 45° zenith angle: ±2%
- 75° zenith angle: ±5%
Wavelength range: 370 nm to 650 nm
Typical Resolution: 1 μmol m^-2 s^-1 (PPFD)
Sensor dimensions:
- Diameter: 2.4 cm
- Height: 3.3 cm
- Cable Length: 5 m
Materials: Anodized aluminum with cast acrylic lens

Requirements

Choose a platform below to see its compatibility requirements.

LabQuest

Interface	LabQuest App
LabQuest 3	Full support
LabQuest 2	Full support ¹
LabQuest	Incompatible

Compatibility Notes

Wireless connection of this sensor to a LabQuest 2 requires a Go Direct Bluetooth Adapter (discontinued) when used with some older LabQuest 2 models.

Computers

	Software
Interface	Graphical Analysis	Graphical Analysis (Web App)
No interface required	Full support	Full support
LabQuest 3	Full support ¹	Incompatible
LabQuest 2	Full support ^{1 2}	Incompatible

Compatibility Notes

Connect this sensor directly to a computer or Chromebook via a USB or wireless Bluetooth^® connection for best results. Alternatively, this sensor is fully supported when used with LabQuest 2 or LabQuest 3 when the LabQuest is connected via Wireless Data Sharing.
Wireless connection of this sensor to a LabQuest 2 requires a Go Direct Bluetooth Adapter (discontinued) when used with some older LabQuest 2 models.

Chromebook

	Software
Interface	Graphical Analysis (Web App)
No interface required	Full support

iOS

	Software
Interface	Graphical Analysis	Graphical Analysis GW
No interface required	Full support	Incompatible
LabQuest 3	Full support ^{1 2}	Full support ^{1 2}
LabQuest 2	Full support ^{1 2 3}	Full support ^{1 2 3}

Compatibility Notes

Connect this sensor directly to a supported mobile device via a wireless Bluetooth^® connection for best results.
iOS and Android^™ devices can only connect to LabQuest 2 or LabQuest 3 via Wireless Data Sharing.
Wireless connection of this sensor to a LabQuest 2 requires a Go Direct Bluetooth Adapter (discontinued) when used with some older LabQuest 2 models.

Android

	Software
Interface	Graphical Analysis	Graphical Analysis GW
No interface required	Full support	Incompatible
LabQuest 3	Full support ^{1 2}	Full support ¹
LabQuest 2	Full support ^{1 2 3}	Full support ^{1 3}

Compatibility Notes

iOS and Android^™ devices can only connect to LabQuest 2 or LabQuest 3 via Wireless Data Sharing.
Connect this sensor directly to a supported mobile device via a wireless Bluetooth^® connection for best results.
Wireless connection of this sensor to a LabQuest 2 requires a Go Direct Bluetooth Adapter (discontinued) when used with some older LabQuest 2 models.

Python

	Software
Interface	Python
No interface required	Full support

Javascript

	Software
Interface	Javascript
No interface required	Full support ¹

Compatibility Notes

A wireless Bluetooth^® connection can be made with Go Direct sensors on any platform running a browser with WebBluetooth support. However, only a few operating systems have been tested and testing has been limited.

LabVIEW

	Software
Interface	NI LabVIEW
No interface required	Full support

What's Included

Go Direct^® PAR (Photosynthetically Active Radiation)
PAR Sensor lens cover
Micro USB Cable

Accessories

Accessory	Order Code	Price
Go Direct^® Charge Station	GDX-CRG	$109.00
Micro USB to USB-C Cable	CB-USB-C-MICRO	$9.00

Replacement Part	Order Code	Price
Micro USB Cable	CB-USB-MICRO	$5.00
Go Direct® 300 mAh Replacement Battery	GDX-BAT-300	$11.00

Free Download

Download the “PAR Attenuation in Water” experiment. The download includes student instructions, instructor tips, and sample data.

Go Direct^® PAR (Photosynthetically Active Radiation)