FAQs
Frequently Asked Questions
Product Operation
What is Purpl PRO?
Purpl PRO is the first affordable, accurate, portable potency measurement device for the cannabis industry. The Purpl PRO is a “laboratory bench” device about the size of a Post-It stack that uses a mobile app to run the system on a smartphone.
How does it work?
The Purpl PRO uses near-infrared spectroscopy, which involves shining light on the sample and analyzing the light returned. In this part of the light spectrum (that is just beyond the red light that 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.
How accurate is Purpl PRO?
The simplest way to put it is the Purpl PRO has a +/- 2% accuracy on THC and CBD. More technically, it’s +/- 1.89% on THC and +/- 0.96% on CBD. We determined those numbers by comparison with lab HPLC measurements. We also have more details on the accuracy for premium models.
Why do samples from the same plant show different results?
Cannabis is a natural product that varies over time and by location. Even the same flower can show different potency levels at the cola compared to the lower canopy. That’s why we recommended grinding your samples to get a result that is an average of these different levels.
How do I get the most consistent results?
First, make sure you operate the Purpl PRO according to its instructions. We designed the Purpl PRO to be easy to use, but it is a scientific testing device.
You’ll want to grind your flower to ensure proper homogenization of the sample and get the most accurate results from the whole flower. Be sure that seeds, stems, and anything that’s not flower are taken out. From there, fill the sample chamber and then compress it with the cap. And you’re ready to test! Keep in mind that results can vary to around +/-2% between readings.
Why use the supplied grinder?
We selected the Storz & Bickel Herb Mill grinder for the Purpl PRO kit because it has extra sharp teeth. This makes for a finer grind, which creates more accurate results.
We also designed the funnel to make for easier product loading into the Purpl PRO. The cleaning brush does a great job of removing any residual bits from the grinder teeth. If you’re used to the SLX Grinder, you may need to grind up the product a little longer to produce a homogenized sample.
For information on how to clean the supplied grinders, please refer to our tech support.
Does Purpl PRO require an internet connection?
Yes, either a WiFi or cell network connection is required for the Purpl PRO to communicate with the cloud servers that compute and store the results. You’ll see an error in the Purpl PRO app if it isn’t connected.
Can Purpl PRO measure extracts?
Yes! We offer an Ethanol-Based Distillates subscription in the Purpl PRO 2 app. Our extract hardware can be used with the Purpl PRO to measure a tiny amount of extract.
Why use the X-Plate & X-Cap for distillate testing?
The X-Plate and X-Cap are essential for accurate distillate test results with the Purpl PRO. The X-Plate securely holds the sample in place, while the X-Cap ensures a proper seal. It allows the spectrometer to reliably measure the sample’s potency.
Can Purpl PRO measure edibles for infused products?
No. Infused products contain ingredients that interfere with the optical measurements.
Can Purpl PRO measure contaminants (pesticides, molds, etc.) or heavy metals?
No. The technology behind the Purpl PRO can only measure down to ~1-2%, and contaminants must be several orders of magnitude lower to be safely consumed.
Product Usage
What other industries use Purpl PRO?
Purpl PRO is geared specifically towards the cannabis industry. However, the near-infrared technology powering Purpl PRO is used in nearly all manufacturing industries, from big agriculture to pharmaceuticals to food & beverage.
Is Purpl PRO a state-certified test method?
No. Most states name only HPLC or GC as certified methods. The Purpl PRO is not intended to replace mandatory third-party testing of final product and is intended to replace R&D testing, which does not require HPLC or GC.
You’ll want to grind your flower to ensure proper homogenization of the sample and get the most accurate results from the whole flower. Be sure that seeds, stems, and anything that’s not flower are taken out. From there, fill the sample chamber and then compress it with the cap. And you’re ready to test! Keep in mind that results can vary to around +/-2% between readings.
What are optimal use-cases for Purpl PRO?
Any time a potency measurement is needed that doesn’t require third-party lab testing. Pheno hunting, optimization of cultivation parameters, R&D testing, transparency during transactions, and many more.
We also designed the funnel to make for easier product loading into the Purpl PRO. The cleaning brush does a great job of removing any residual bits from the grinder teeth. If you’re used to the SLX Grinder, you may need to grind up the product a little longer to produce a homogenized sample.
For information on how to clean the supplied grinders, please refer to our tech support.
Is Purpl PRO supposed to eliminate outside lab-testing?
No. Third-party testing is required for quality assurance in final products. But the Purpl PRO can be used for all cases where third-party testing is NOT required.
What can Purpl test for?
Currently, total THC and total CBD in cured, ground flower, as well as measurement of moisture and water activity. The Purpl PRO now also allows for potency measurement of extracts.
How is Purpl PRO different than HPLC or GC?
Both HPLC and GC require a cannabis sample to be dissolved in liquid solvent to strip away the non-cannabinoid substances, then this liquid is pushed through small tubes until an optical sensor records the amount of cannabinoid. Both techniques require continual calibration and cleaning, which require trained operators. Between the cost of the instruments, the solvents, calibration materials, and the personnel, these techniques run well into the tens of thousands of dollars to set up and operate.
The Purpl PRO uses light to measure a ground sample directly, comes with its own calibration module that is indefinitely reusable and is usable by anyone. It also fits in a pocket, costs $1,995, and leaves the sample usable after measuring.
Will Purpl PRO match my lab values?
In some cases it will, and in others it might not. The reason for this is that different labs generally don’t obtain the same results even from the same flower sample (several published reports show this variation). Depending on the exact procedures your lab uses, the alignment of the Purpl PRO results with your lab may differ. But even if the Purpl PRO provides a different absolute result than your lab, it can still be used for comparisons between flowers, establishing trends in potency, pheno- hunting, etc.