Purpl PRO utilizes near-infrared spectroscopy, which involves shining light on the sample and analyzing the light that is returned. In this part of the light spectrum (just beyond the red light human eyes can see) molecules react to specific regions of the light to generate a “molecular fingerprint” that can be correlated with concentration.

The Purpl PRO was calibrated against HPLC measurements from multiple state-certified testing laboratories.

Currently, Total THC and Total CBD in cured, ground flower. In 2020 a software update will also allow measurement of moisture and water activity. Towards the end of 2020 it will also allow potency measurement of extracts.

Overall, Purpl states a +/- 2% accuracy on THC and CBD for simplicity. Statistically, it is +/- 1.89% on THC and +/- 0.96% on CBD, determined by comparison with lab HPLC measurements.

In short: nature. Cannabis is a natural product that varies over time and by location. Colas and larf on the same plant are so named because of the difference in their flowers due to location on the plant.

Even parts of the same flower generally have different potency at the cola than the lower canopy. As such, we recommend grinding a sample to get an averaged result.