# Select a Protocol
# What is a Protocol?
These are instructions that are sent to the Instrument on how to conduct a measurement. Which parameters you measure will be dependent on which protocol you choose for your Project.
Tip
Read the protocol description carefully to be sure that it is measuring what you want to measure and that it is compatible with your Instrument.
Before field collection, test the selected protocol on representative samples. Confirm the instrument model and firmware requirements, expected measurement duration, sample positioning, output parameters, and quality warnings. Record the protocol name and version in the study plan so the measurement method can be reproduced.
# Choose a Protocol
- Open the Protocols step in the Project builder.
- Select the relevant protocol category tab.
- Select a protocol from the available list.
- Read its description and confirm device compatibility.
- If needed, search protocols shared by collaborators.
- Select Save and Next.
The initial list includes available preselected protocols, protocols created by the signed-in user, and protocols already assigned to the Project.
Custom protocols
Create and test custom protocols in the PhotosynQ Desktop Protocol Editor. After synchronizing them to PhotosynQ, return to the builder and select the required protocol.
# Does the order of Protocols matter?
The protocols will run in the order that you select them. Depending on what you are measuring, it may be important to keep them in a certain order. For example, measure photosynthetic yield before measuring relative chlorophyll content so that the LED's from the relative chlorophyll content measurement do not affect your photosynthetic yield value.
Keep the protocol order consistent for all experimental units. If the order must change after collection begins, document when and why it changed and treat the resulting groups as potentially different measurement conditions during analysis.