PPFD Canopy Grid Survey

Required tools

• quantum/PAR sensor
• grid or marked measurement positions
• measuring tape
• record sheet or digital map

Before starting

• Warm up and operate fixtures according to their normal measurement condition.
• Define the measurement plane before starting.
• Keep sensor orientation consistent and avoid shading it with the operator.

Step 1

Define the grid

Mark repeatable positions across the target area and record the grid spacing and measurement height.

Record: Record grid dimensions, point labels, and target-plane height.

Step 2

Stabilize lighting

Set fixtures to the normal output and configuration being evaluated and allow them to reach a stable operating condition if required.

Record: Record fixture state, dimming level if known, and relevant environmental or curtain state.

Step 3

Measure each point

Place the sensor at each grid point in the same orientation and record the stabilized PPFD value.

Record: Record PPFD for every point with units.

Step 4

Summarize distribution

Calculate or report minimum, maximum, average, and obvious low/high zones without hiding individual grid values.

Record: Record summary values and a grid map.

Step 5

Preserve comparability

Save enough setup detail that the same grid can be measured again after a change.

Record: Record fixture height/position and canopy or reference-plane description.

All planned grid positions have a recorded value.

Measurement plane and sensor orientation are documented.

Units are PPFD units and are not confused with lux or fixture power.

A PPFD map describes the measured plane at that moment; it does not by itself describe leaf-level interception throughout a three-dimensional canopy.