Since the passage of SQ788, the number of medical marijuana dispensaries in the state of Oklahoma has exploded, with over 1500 licenses for them approved by the Oklahoma Medical Marijuana Authority to date. All dispensaries are required by the State Weights and Measures program to be using a NTEP-approved scale to weigh out their product. However, the precision measurement experts at Cross are finding that there is considerable confusion about what exactly is a legal for trade scale and what that means in practice.
NTEP-Approved Scaled for Marijuana
All scales that are used for commercial purposes – meaning they are used to buy or sell by weight – must be approved by the National Type Evaluation Program or NTEP. This means the manufacturer of the scale has had it evaluated by NTEP and that it meets all the requirements of NIST’s Handbook 44. All scales which have NTEP approval and meet any specific local requirements are deemed legal for trade. In addition to the operation and resolution of the scale, there must be documentation of the transaction and, if the sale is done face to face, the customer must be able to see the weight of the product at the time of purchase.
All of this means that you have to have the right scale with the right accessories if you’re a medical marijuana dispensary in Oklahoma.
Receipt and Display
Let’s start with the simple things first: the receipt and the display. You must be able to give your customer a receipt for the transaction. If you are selling the product face to face, as opposed to pre-weighed, the customer needs to be able to see the weight, which usually means they need an auxiliary display. For both, your scale needs to be able to communicate, either through RS232, USB or Ethernet. A scale that cannot transmit data is not acceptable.
Capacity and Resolution
The scale also needs to have the correct capacity and resolution for your commercial needs. The capacity is determined by the largest weight you are likely to put on the scale. For single packages of medical marijuana, a 620g capacity scale should be more than adequate. If you plan on weighing your incoming bulk product with the same equipment, consider a scale with a higher capacity.
The resolution of the scale is based on what the minimum weight you will sell is. Whether you are selling flower or extract, a reasonable minimum would be 0.5g. It’s industry best practice to have ten times more resolution than your minimum amount, so you’d want a scale which measures to 0.05g. This translates to a Class II scale with 10,000 divisions or more. A good example of this is the Ohaus Scout SJX1502. It’s got a 1500g capacity and can be set up to be legal for trade with a 0.1g resolution, giving it 15,000 divisions.
Stable and Repeatable Measurements
In addition, the scale must also give stable and repeatable measurements under normal conditions. If the resolution is too small, external influences in the environment, like drafts, noise or vibrations may prevent the scale from stabilizing and therefore it can’t record an accurate weight. So the scale needs to be precise enough to weigh your smallest amount but stable enough to give repeatable measurements.
How Can Cross Help Your Operation?
In the field of metrology, there are many standards to follow to ensure reliable calibration or inspection. At Cross Precision Measurement, we are an ISO 17025 accredited calibration laboratory that adheres to standards set out by A2LA, NTEP, NCWM, and NIST (specifically, HB44). With our decades of experience and expertise, we make sure you get trustworthy, repeatable metrology products, services, and solutions.
The Precision Measurement group of Cross Company provides industry-leading calibration, inspection (on-site or in-lab), equipment repair, and metrology equipment (torque, scales, and other dimensional metrology tools) to manufacturers, commercial facilities, laboratories, and anyone else in need of accurate measurement and results. Through our extensive network of calibration labs, we can get you the metrology services you need to ensure your equipment is reading right every time. Contact Cross Precision Measurement today
