Conversion - Instantaneous PPFD to Integrated PPFD - A-Grade Hydroponics

Conversion - Instantaneous PPFD to Integrated PPFD

Note: To be able to read PPFD or instantaneous PPFD you will require an accurate quantum meter to take the readings, such as the Apogee MQ-500. 

Most light meters measure the instantaneous photosynthetic photon flux density in µmol m-2 s-1 and yet plant growth is determined by the integrated daily photosynthetic photon flux density in mol m-2 d-1.

Here is how to convert from µmol m-2 s-1 to mol m-2 d-1 when using electric lights.

There are 3600 seconds in an hour. If the electric light output is constant, the instantaneous PPFD can be added up (integrated) over an hour.

Therefore 1 µmol m-2 s-1 = 3600 µmol m-2 h-1.

This must be divided by a million (1,000,000) to convert from micromoles to moles: 3600 µmol m-2 h-1 = 0.0036 mol m-2 h-1.

If the electric lights are on continuously (24 hours), the hourly PPFD must be multiplied by 24 to get the daily PPFD: 0.0036 mol m-2 h-1 = 0.0864 mol m-2 d-1.

There are 86,400 seconds in a day (3600 x 24 hours) so the daily PPFD can be calculated directly from the instantaneous PPFD from the following equation: µmol m-2 s-1 multiplied by 86,400 and divided by 1,000,000 = mol m-2 d-1.

So: 1 µmol m-2 s-1 = 0.0864 mol m-2 d-1 with continuous light

 

These conversions are accurate only under electric lights. The integrated daily PPFD from sunlight changes during the day so a single measurement cannot be used to estimate daily PPFD.

 

Daily PPFD Reference Table

24-Hour Photoperiod

Instantaneous PPFD
(µmol m
-2 s-1)

Daily PPFD
(mol m
-2 d-1)

10

0.864

100

8.64

200

17.28

300

25.92

*600

*51.84

1000

86.40

2000

172.80

 

16-Hour Photoperiod

Instantaneous PPFD
(µmol m
-2 s-1)

Daily PPFD
(mol m
-2 d-1)

10

0.567

100

5.67

200

11.52

300

17.28

600

34.58

*1000

*57.60

2000

115.20

   

12-Hour Photoperiod

Instantaneous PPFD
(µmol m
-2 s-1)

Daily PPFD
(mol m
-2 d-1)

10

0.432

100

4.32

200

8.64

300

12.96

600

25.92

1000

43.20

*1300

*56.23

2000

86.40

*There are 50 to 60 moles per m2 day on sunny summer days in outside areas without any shade.

 

Reference: https://www.apogeeinstruments.com/conversion-instantaneous-ppfd-to-integrated-ppfd/

#growwithus 

Categories

> Propagation
> Hydroponic Equipment
> Plant Nutrition & Health
> Pest & Disease
> Hydroponic Environment
> Harvest
> Geek Out With A-Grade
> Water Control
> Plant Training
> Grow Medium
> Troubleshooting
> Hydroponic Basics

Other Tutorials

Growing Autoflowers
Growing Your Own Food - How to Germinate Seeds
How To Grow Food Indoors
The Benefits of Hydroponic Strawberry Growing
How to start growing plants indoors?

premium hydroponic store

We're committed to helping communities in Australia grow
Shop now