|Precision Weighing Balances offers a large selection of "Legal-for-Trade" balances. You can see all the legal for trade scales we offer HERE. Our most popular "Legal-for-Trade" scales are the Mettler JL602GE, Ohaus Scout SJX1502N/E, AND FX300iN, CAS SW1-20LB, Mettler Toledo JP32001G/A, Chatillon 0723TG, CAS S2000 Junior, Mettler-Toledo JS1603C/A, Healthometer 753KL, Ohaus A71P30DNUS, CAS SW1-50LB, MettlerToledo JL6001GE, Mettler JS4002G/A, Mettler Toledo JS8001G/A, A&D Weighing HL-3000WPN, AND EK1200i, A&D GF300P, Scientech ZSP400NP used in businesses for medical marijuana, laundromats, jewelers, pharmacy compounding, tobacco, coffee or candy stores. "Legal for Trade" scales are generally considered those scales which are intended by the manufacturer for use in "commercial" applications where product is sold by weight. While the definition of commercial applications may vary slightly among different weights and measures jurisdictions, NIST Handbook 44 (General Code paragraph G-A.1.) and NIST Handbook 130 (Uniform Weights and Measures Law, Section 1.13.) define Commercial Weighing and Measuring Equipment as follows:
".....weights and measures and weighing and measuring devices commercially used or employed in establishing the size, quantity, extent, area, or measurement of quantities, things, produce, or articles for distribution or consumption, purchased, offered, or submitted for sale, hire, or award, or in computing any basic charge or payment for services rendered on the basis of weight or measure."
"Legal-for-Trade" balances typically cost a lot more than "Not Legal for Trade" since extensive testing is required to achieve a Certificate of Conformance. Legal for trade scales evaluation are performed on the design of the device, operation, environmental factors and marking requirements. Several increasing/decreasing load and shift tests are conducted. The scales are tested over a temperature range of 10°C to 30° C (50° F to 86° F) for NTEP Approval. A load of approximately one-half capacity is applied to the scales at least 100,000 times.
The stringent testing requirements are usually only achieved in high quality balances incorporating the use high quality electronic components and superior engineering. Precision Weighing Balances offers a huge selection of "Legal for Trade" balances.
Many people ask - why should I buy a weight measurement instrument that is "Legal-for-Trade" when I don't intend to use the balance in a commercial weighing application? In our opinion, when you purchase a "Legal-for-Trade" balance you will know you are getting a quality precision weighing balance that has undergone independent testing to verify the unit meets the manufacturer's specifications. If there is a comparable model built by another manufacturer why wouldn't they attempt to achieve "legal-for-trade" status? Is the reason they typically can't pass the requirements?
For this reason we also recommend A&D & Mettler balances over any other manufacturer because of the numerous "Legal-for-Trade" scale they manufacturer. Take a look at some of the other scale manufacturers and if you see that they don't offer any "legal-for-trade" scales it is usually since they can't produce a quality balance that can meet the stringent test.
To achieve a Certificate of Conformance for "Legal-for-Trade" status the testing emphasis of the evaluation is to verify the balance meets the performance specifications. Typical testing includes:
- Balance is tested over a specified voltage range. Example: 100 to 130 VAC and 10.0 to 12 VDC.
- Temperature. i.e.: Influence factor tests were conducted at 20 °C, -10 °C, 5 °C, 40 °C and 20 °C.
- Accuracy - A load of one-half capacity is placed on the scales over 100,000 times.
State weights and measures jurisdictions have adopted Handbook 44, so, except in instances where an individual State has adopted more specific language to define the term "commercial", this general definition would apply. The determination that a scale is a "legal for trade scale" begins with the manufacturer who designs a scale to be used in commercial applications. A scale that meets all requirements of NIST Handbook 44 and applicable State and local weights and measures requirements would be deemed to be suitable for "legal for trade" or commercial applications.
The National Type Evaluation Program (NTEP) performs evaluations of weighing and measuring devices for compliance with NIST Handbook 44. Many States require an NTEP Certificate of Conformance for any device to be installed in a commercial application. (You can review these states that require NTEP Certificates and States that have Voluntary Registration of Service Agencies and Service Persons (VRSA) by downloading this PDF file. NTEP testing does not "assign a legal for trade status" to a device, it simply indicates that the device evaluated has been found to comply with Handbook 44. In a non-NTEP State, for example, a device may not need an NTEP Certificate of Conformance to be used in a commercial application; it may simply be required to meet Handbook 44 requirements and comply with any additional State weights and measures requirements. The final approval of the device in a specific installation rests with the State, Local, or Federal weights and measures official who determines if the device meets all Handbook 44 requirements, including installation and suitability requirements.
Some manufacturers who design a scale which is not intended for legal for trade or commercial applications may mark their scales with the phrase "Not Legal for Trade" to help ensure that the scale is not used in a commercial application. MyWeigh Scales marks their Palmscale 7 pocket scale "Not Legal for Trade" on the bottom side of the scale.
The accuracy classes of scales, the manufacturer assigns the accuracy class of the device based on its design and intended application. Handbook 44 includes specifications and tolerances for each accuracy class. In order to be approved for use as a particular accuracy class scale, the device must meet the specifications, tolerances, use, and other requirements for the accuracy class. An overview of the typical applications for the various accuracy classes is as follows:
Class I and II devices are generally used in laboratory and higher precision weighing. (Class I 100,000+ divisions) (Class II 10,000 - 100,000 divisions). Examples of a Class I Approved Balance is the Mettler JS1603C/A - 320,000 divisions or Ohaus AX224N - 220,000 divisions. Examples of a Class II Approved Balance are the Mettler JL602GE, A&D FX-1200iN, Mettler JS6002 or Scientech ZSE250
Class III devices are commercial weighing devices not specified in other accuracy classes and also includes scales such as postal scales, animal scales, and others. (Class III 1,000 - 10,000 divisions) Examples of a Class III Approved Digital Scale include the A&D EK600i, CAS NC-1 500, Ohaus A71P30DNUS and CAS SW-1-20LB (SW-20).
Class IIIL includes scales such as vehicle, axle-load, livestock, railway track, crane, hopper (other than grain), etc.
Class IIII includes wheel load weighers and portable axle-load weighers for highway weight enforcement. (See the Scales Code in Handbook 44 for further details.)
A lot of people call us to explain what "d" and "e" means so here is the answer:
The value "d" is the smallest division shown on the scale display.
The value "e" is the verification scale division. It represents the stated accuracy of a scale when the scale display has extra units added in order to expand the resolution. The verification scale division (e) may be larger than the displayed scale division (d) for some devices.
So how will a Weights & Measures Inspector classify the readability of the weighing device when "d" and "e" are not equal? For example the AND EK6100J and Mettler JL6001GE has a maximum weighing capacity of 6100g and 6200 grams respectively with the display increments in 0.1 gram divisions. The “d” (value of scale division) is 0.1 grams and the “e” (value of verification scale division) is 1 grams.
The simple answer is that legally, “d” cannot be considered in a commercial transaction. If you have a scale that has d = 0.1 g and e = 1 g, then legally the scale is a 1 gram scale and will be tested and evaluated accordingly. “d” must display on the scale as distinct from all of the other digits, it can be bracketed, it can be grayed out, it can be a smaller font, etc.
Now there are some states that might accept the "d" value today, but eventually states are only going to accept "e". In November of 2015 we spoke with Nicholas Brechum, Measurement Standards Program Manager for the State of Colorado and Colorado is accepting "d" for the medical marijuana dispensaries. Colorado Department of Agriculture requires a cannabis dispensary that intends to sell quantities of medical marijuana of less than 1 ounce to have a weighing device NTEP Class I or Class II scale with a division of 0.01 grams or less. So in Colorado a medical marijuana dispensary meets the scale requirements when purchasing the Mettler JL602GE, Mettler-Toledo JS3002GA, Mettler Toledo JS4002G/A, Mettler Toledo JS6002GA, A&D Weighing FX1200iN, FX2000iN, or FX3000iN, Ohaus AX622N/E, AX1502N/E, AX2202N/E or AX4202N/E. All for the aforementioned digital scales have "d" = 0.01 grams and "e" = 0.1 grams.
States like California and Oregon will only accept "e". For retail stores that sell less than 1 ounce of cannabis you will need a NTEP Class I or Class II scale that has "e" division value of 0.01 grams or less. So if you operate a medical marijuana dispensary in California and Oregon the weighing device that meets the requirement would be any of the following AND Weighing FX120iN, FX200iN, FX300iN, Ohaus AX223N/E, AX423N/E, AX423N or AX523N/E. All for the aforementioned digital scales have "d" = 0.001 grams and "e" = 0.01 grams.
Oregon requires all marijuana growers, packagers, and retailers to have a commercial scale with a valid National Type Evaluation Program Certificate of Conformance (NTEP CC). Its not sufficient for a scale manufacturer to say that it is “legal for trade”, it must have the NTEP CofC. Once the scale is installed the operator must complete a Placed in Service Report and complete a License application. Once these two documents are submitted to Oregon Department of Agriculture then the scale can be legally used. No need to wait for the Weights and Measures inspector to show up; The initial inspection will occur normally within 30 days of receipt of the paperwork.
When selecting a digital scale the scale must also be suitable to the application. You can assess suitability for your weighing application by two basic questions; What is the minimum weight of product to be weighed on the scale? What is the maximum weight of product to be weighed on the scale? The minimum weight will tell you the maximum allowed division size of the scale, the maximum weight determines the required capacity. The scale must normally read 20 divisions for the minimum weight to be sold over it.
1) Your customer expects to weigh out marijuana at the counter in a range from 1 gram to 200 grams.
1 gram / 20 divisions = 0.05 grams / division
Capacity should be at a minimum 200 grams.
Any scale having a division size of not more than 0.05 grams will be suitable. If you had a scale 200 grams x 0.01 grams capacity it would easily serve the customer’s needs.
There is a functional limit on the scale’s division size, if the division is too small and the environment in the store is drafty, noisy, or there are a lot of vibrations then the scale will never settle down and will be ruled as unsuitable based on the operating environment. The Weights & Measures Inspector will look at the requirements in the scale’s user manual when assessing suitability of the environment when it appears that the scale is not performing as it should. Legal for trades scales should give stable and repeatable measurements under normal conditions.
2) You customer expects to weigh out marijuana at the counter in a range from 1 gram to 30 grams but also wants to use the scale to receive up to 2 lb. packages of marijuana from their supplier.
1 gram / 20 divisions = 0.05 grams / division
1 lb. = 453.59237 grams
Capacity should be 2 lb. or 907.18 grams
In this case the store might need a 1,000 gram x 0.01 gram scale to meet the requirement
3) A grower ships marijuana in 2 to 5 lb. bundles to a marijuana processing facility.
2 lb. / 20 divisions = 0.01 lb. / division
Capacity should be not less than 5 lbs.
In this case a conventional 30 lb x 0.01 lb grocery store deli scale or bench scale like the A&D HV-15KWP, or even the very affordable CAS SW-1-20LB (offers 20 lb weighing capacity and increments in 0.01 lb intervals) would be appropriate to weigh the product. Please note if you are using medical marijuana dispensary software like BioTrackTHC you'll need a scale with an RS232 interface to transfer the weighing results from the scale to your computer. The CAS SW-1-20LB does not have any communication port so the HV-15KGL would be more appropriate since the HV-15KGL does have a serial port. Whatever medical marijuana dispensary software you select you always want to verify which scale manufacturer the software is designed to work with BEFORE you purchase your scale. There are numerous Medical Marijuana Seed to Sale software on the market like BioTrackTHC, MJ Freeway, Webjoint, Ample Organics ERP, Green Bits, PROTEUS420, IndicaOnline EMR, Agrisoft Seed to Sale and numerous others and some offer a very limited choice of scales their software will communicate with.
If the grower wanted to do smaller lots it might make more sense to have 2 scales with different weighing ranges rather than to try and buy 1 that covers such a large range.
Lastly one always needs to look at the value of a division size. Weights and Measures does not consider commodity pricing when requiring division size, rather they enforce the requirement that a division be not more than 5% of the total transaction. You may care about this and may wish to buy a more expensive scale to get a better resolution/accuracy. The inspector only require that the scale be stable in the environment that they hope to use it in.
The ability to perform calibration of scales varies greatly across the United States. Some states allow the owner of the scale to calibrate the digital scale prior to putting the weighing device in service while other states require you to have a licensed scale technician from your particular state perform the calibration. We always recommend you call your Weight & Measures Inspector's Office to see if you can perform your own calibration. In Oregon the scale owner or operator is allowed to calibrate and seal the scale. That said, you will need a suitable calibration weight to complete this task. I can tell you that measurement inspectors have tagged numerous marijuana scales for not meeting tolerance requirements simply because the scale did not have an initial calibration done when it was unboxed and plugged in.
All scales need to be leveled (adjust the leveling feet until the leveling bubble is centered) and calibrated before use. People seem to have a lot of confidence that the scale will read correctly without any extra effort and it just doesn't work that way most of the time. Your scale needs to be calibrated at the place of installation where the scale is used. Every location in the world is positioned differently to "magnetic north" and therefore the acceleration of gravity is slightly different. Add to this barometric pressure effects the acceleration of gravity depending upon your location's altitude to sea level.
Selection of a suitable test weight depends on both size and resolution. If a 0.01 g scale requires a 1 kg test weight to calibrate it then you need a test weight that is accurate to within 1/3 of the scale's division size or 0.01 g / 3 = 0.0034 g = 3.4 mg. An ASTM Class 1 1kg standard has a tolerance of 2.5 mg. If you were calibrating a 0.1 g scale, 0.1 g / 3 = 0.034 g = 34 mg. An ASTM Class 4 1kg standard has a tolerance of 20 mg. (Please reference our Metric Weight Tolerances HERE)
The information listed on this page is only a summary regarding Legal for Trade Scales and Balances. There is an abundance of information on the Internet regarding this information in greater detail. A great source of valuable information can be found at the National Institute of Standards & Technology Office of Weights and Measure. You can also search NIST's web site and download the Certificate of Conformance here. We also recommend you contact your State, Local, or Federal weights and measures official for more detailed information.
Additional sources include the Scale Manufacturers Association. Oregon Department of Agriculture's Weights and Measures has their NTEP handout online here where you can learn more about the language related to weights and measures. Washington State Department of Agriculture outlines their recreational marijuana regulation scale requirements HERE.
In closing, selecting the correct scale for your commercial application can sometimes be best answered by the people administrating the weights and measure program for your state. We offer a link that lists as the State W & M Directors with their phone number e-mail address and web site here.
Special Note: Many of the legal for trade balances are now being marked "Not for Direct Sales" and we are receiving many calls from concerned customers thinking their scale is not Legal for Trade if the balance has a label on the display marked "Not for Direct Sales". Please be assured the balances and scales that Precision Weighing Balances markets in our "Legal For Trade Scales" category on our home page are Legal for Trade.
Many of the scales are labeled "Not for Direct Sales" since Weight & measures now want both the operator of the scale and the consumer to be able to see the display showing the weight. If the scale only has one display then the scale should not be used for a direct transaction between the operator of the scale and the consumer. For direct face to face transactions with the consumer you are required to purchase an optional auxiliary display so the consumer can see the weight on their on display. There are some scales we offer where you can purchase an optional auxiliary display and if this is your situation we recommend you give us a call prior to making your purchase.
Below is an e-mail we received from Jim Truex, NTEP Administrator at National Conference on Weights and Measures.
Sent: Friday, December 26, 2008 6:15 PM
To: Precision Weighing Balance
Cc: Don Onwiler
Subject: not for direct sale labeling
Please don't confuse the terminology "not for direct sale" with "not legal for trade", as they are not the same. In weights and measures terminology a direct sale is one where both the buyer and seller are present. NIST Handbook 44 requires the customer to be able to witness the transaction and transaction information form a reasonable position in a direct sale application.
I assure you the scales are NTEP approved, are legal for trade and are legal for use in commerce.
National Conference on Weights and Measures
1135 M Street, Suite 110 / Lincoln, Nebraska 68508
P. 402.434.4880 D. 740.919.4350 F. 402.434.4878