“Get the calibration pad” – this is task no.1, if you want to measure leaf area effectively and accurately with Petiole. In fact, the link to download your calibration pad will arrive directly to the email, which you provided for authorisation. However, if you still don’t have the this important piece of equipment for leaf area measurement, then it’s time to have it.

Explanation of the Need of Calibration Pad

Firstly, you may think that this is unusual task – to get the calibration pad. However, this is not true. Indeed, you cannot start to use Petiole Leaf Area Meter without calibration. Simply, your camera won’t be ready for precise measurement.

In brief, as you can see in the video below, calibration pad is an essential part of the equipment for leaf area measurement with Petiole app.

As of now, we are NOT selling calibration pads. However, we give them for free to anyone! You can find Petiole calibration pad using the links provided below.

Calibration Pads for Petiole Pro

Surely, we understand that the size of leaves varies. And the distance between the camera and the leaf varies as well. Hence, based on these two aspects, we’ve created four types of calibration pads.

All of them are available in tree-friendly mode, on one A4 sheet of paper. Please, follow this link to download the pads for camera calibration of Petiole Pro App.

Calibration Pads for Petiole App

However, if you use Petiole App then as a calibration pad you need to choose your calibration pads from the range below.

For big leaves we recommend to use the Petiole App calibration pad #15

If you have leaves of the medium size, then use Petiole App calibration pad #10

Leaf area of small leaves requires calibration pad #7

Lastly, for very small leaves you can apply the calibration pad #5

IMPORTANTLY: you need different calibration pads for Petiole App and Petiole Pro. Calibration pads for Petiole App do NOT work with Petiole Pro. Please, use the correct calibration pads respectively.

Accuracy Checking Pad for Petiole Pro

Before measuring leaf area of your plant leaves, it is possible to check the accuracy of the measurements. Watch this brief video for more details:

If you wish to have accuracy checking pads, please download them using the links provided below:

• Circles with area 0.785 cm2 are available here
• Circles with area 1.767 cm2 are available here
• Two accuracy checking pads are available in the same file here (size: 2.5Mb)

Step-By-Step Instruction How to Get Your Calibration Pad

1. Firstly, check available four different pads.
2. Then choose your own calibration pad depending on (a) distance between a leaf and your camera and (b) size of your leaves.
3. Obviously – you can print your pad on A4 paper. Preferably, you need to use card paper to make your pad’s life longer.
4. Finally, you have to cut your pad with scissors. If you can laminate, do it! And then your calibration pad will be ready to use.

Problems with Camera Calibration

From time to time, our customers have problems with camera calibration. Firstly, we’ve tried to create a brief guideline how to solve this problem.

As a matter of fact, the problem is not related to the pad or stand for Petiole app. Basically, the biggest hidden challenge is linked to the camera of your smartphone. Unfortunately, in reality not all the producers of modern phones are responsible.

Sadly, but they use cheap materials and simplified software for cameras. Hence, the mobile app, which is perfectly working on most Android-based devices, have lots of problems on unique cheap items.

Anyway, if you have any problems with Petiole, then let us know about them. Hence, we’ll try to be helpful.

Finally, we want to thank you once again for your continued support and interest in Petiole products. Also, please, do not hesitate to subscribe for our Youtube, Facebook or Twitter to get the most interesting updates.