What Is NTEP? A Guide to NTEP Certified, Legal-for-Trade Scales (Classes, CCs and Placing in Service)
Short answer: an NTEP certified scale is a model that passed type evaluation under the National Type Evaluation Program, run by the National Conference on Weights and Measures (NCWM), and received a Certificate of Conformance (CC) showing it meets NIST Handbook 44. If you sell, buy or charge for anything by weight (deli, produce, shipping charges, gold, scrap, livestock), you need an NTEP approved scale of the right accuracy class, installed and placed in service by a registered technician. For lab work, QC and general testing, NTEP is optional.
“Legal for trade”, “NTEP approved”, “NTEP certified” and “Class II” all show up on scale listings, and the differences matter when an inspector tests your scale. This guide explains what NTEP means, how to read a Certificate of Conformance, which accuracy class fits your business, and how to get a legal-for-trade scale placed in service.
What does NTEP mean?
NTEP stands for the National Type Evaluation Program. The program is administered by the NCWM. Manufacturers submit a model to an NTEP laboratory, which tests it against NIST Handbook 44, the national code of specifications and tolerances for commercial weighing and measuring devices. Models that pass receive a Certificate of Conformance with a number (for example, CC 04-019 for the A&D EK-i series).
NTEP evaluates the type (the model design), not each individual scale. Each scale used in commerce still has to be installed correctly, calibrated and placed in service, and it’s inspected in the field by state weights and measures officials.
NTEP approved, NTEP certified, legal for trade: same thing?
In everyday use, yes. “NTEP approved”, “NTEP certified” and “legal for trade” all describe a scale whose model holds an NTEP Certificate of Conformance and is set up in its approved configuration. Look for the CC number and accuracy class on the scale’s data plate and in the product specifications.
Accuracy classes: which one do you need?
Handbook 44 sorts commercial scales into accuracy classes, based mainly on the number of verification divisions (n), which is capacity divided by the verification division (e).
| Class | Typical number of divisions (n) | Typical uses |
|---|---|---|
| I | 50,000 and up | Precision laboratory weighing |
| II | Up to 100,000 | Precious metals and gems, laboratory weighing, prescription weighing |
| III | Up to 10,000 | Most commercial weighing: retail and deli, shipping and postal, bench and floor scales, animal scales |
| III L | 2,000 to 10,000 | Vehicle, livestock, railway track, crane and hopper scales |
| IIII | 100 to 1,200 | Wheel-load weighers and portable axle-load weighers for highway enforcement |
Buying or selling precious metals by weight? Choose a Class II model such as the A&D EK-1200i (1200 g × 0.1 g, CC 04-019), the A&D FX-200iN or the A&D FX-300iN. For shipping charges and retail counters, a Class III scale such as the Brecknell PS-USB-150 (150 lb × 0.05 lb, NTEP) fits. For side-by-side Class II picks from 122 g to 12 kg, see our legal for trade jewelry scale guide.
d vs e: why a 0.001 g balance can be legal at 0.01 g
Many legal-for-trade balances show two values. d is the displayed division, the smallest step the display shows. e is the verification division used for legal-for-trade testing and tolerances. On the A&D FX-i series NTEP certificate (CC 08-045), for example, the FX-300iN has d = 0.001 g and e = 0.01 g. In trade, the 0.01 g value is the one that counts. When you compare legal-for-trade scales, compare e, not just d. Our FX-120i vs FX-120iN vs FX-300i comparison shows how the e = 10d and e = d modes work on the FX-iN series.
How to read a Certificate of Conformance
- CC number and models covered. One certificate often covers a whole series, with a table of models, capacities, nmax, e and class.
- Accuracy class for each model or configuration.
- Approved features. Units, tare, and which features are not legal for trade (counting is a common one and is labeled on the scale).
- Sealing. How the calibration is secured, such as a wire seal through the calibration switch cover.
- Temperature range and any special conditions of use.
You can search certificates on the NCWM website. Need help confirming a model’s CC before you buy? Ask us; we’re an authorized dealer for the brands we sell.
Who needs an NTEP scale?
- Grocery, deli, produce and bulk food counters that price by weight.
- Shipping stores and businesses that charge customers for shipping by weight.
- Gold buyers, jewelers, pawn shops and coin dealers buying or selling by weight (Class II).
- Recyclers and scrap yards, feed and seed, agriculture and livestock sales.
- Cannabis and dispensary operations, where state programs typically require legal-for-trade scales (see our best scale for cannabis dispensaries guide).
- Food and product packers that print a net weight on the label (see our checkweigher scale guide).
- Any business where the weight sets the price.
Labs, QC benches, schools, reloaders, pharmacies weighing for testing, and general shipping prep can use any accurate scale. Many still choose NTEP models for the build quality and the documentation.
Getting a legal-for-trade scale placed in service
- Buy an NTEP scale of the right class and capacity for your application.
- Install it level, on a solid surface, where it will be used.
- Have a registered service technician test, calibrate and seal it. In Texas, the licensed service company reports the work to TDA on an RWM-780. Read our RWM-780 guide.
- Keep it in tolerance with regular checks and scheduled calibration.
MNM Scales is TDA licensed with registered technicians who can inspect, calibrate and place legal-for-trade scales in service across the Houston area, with Dallas, Austin and San Antonio on request. On-site service is a $295 service call plus $2 per mile round trip, and our technicians bring their own test weights.
Popular NTEP legal-for-trade scales at MNM Scales
- A&D EK-1200i, 1200 g × 0.1 g, Class II: gold, jewelry and pawn counters
- A&D FX-200iN and A&D FX-300iN: Class II precision balances
- Brecknell PS-USB-150, 150 lb × 0.05 lb: NTEP shipping scale with USB and RS-232
- MNM Scales AHS-60 hanging scale, 60 lb × 0.05 lb, NTEP: agriculture, produce and recycling
- MNM Scales Echelon EH 48″ × 48″ floor scale, 5,000 × 1 lb, NTEP: pallets, recycling and warehouses
Browse all NTEP legal-for-trade scales or NTEP precision balances. MNM Scales has been in business for over 30 years, is one of the largest scale distributors in the country and carries the largest selection of NTEP scales in every category.
Calibration for NTEP scales
Add calibration to your order so the scale arrives calibrated with a certificate, then have it placed in service on site. Prices by capacity:
| Maximum capacity | In-house calibration with certificate | NIST calibration with NIST-traceable certificate |
|---|---|---|
| Up to 2.2 kg (about 5 lb) | $95 (add to cart) | $395 (add to cart) |
| Over 2.2 to 6.2 kg | $195 (add to cart) | $495 (add to cart) |
| Over 6.2 to 35 kg (about 14 to 77 lb) | $250 (add to cart) | $595 (add to cart) |
| Over 35 to 150 kg (about 77 to 330 lb) | $350 (add to cart) | $750 (add to cart) |
| Over 150 kg (floor and large platform scales) | $495 (add to cart) | $995 (add to cart) |
More: how often to calibrate and in-house vs NIST-traceable certificates.
Not sure which class you need? Tell us what you weigh and how you sell it, and we’ll match you with the right NTEP scale.
Frequently asked questions
What does NTEP certified mean for a scale?
It means the scale’s model passed type evaluation under the National Type Evaluation Program, administered by the NCWM, and holds a Certificate of Conformance showing it meets NIST Handbook 44 for commercial use.
Do I need an NTEP scale?
You need an NTEP approved scale when weight determines a price or charge, such as retail and deli counters, shipping charges, precious metals, recycling and livestock sales. Labs, QC and general testing can use any accurate scale.
What is the difference between Class II and Class III scales?
Class II scales have up to 100,000 verification divisions and are used for precious metals, gems and laboratory weighing. Class III scales have up to 10,000 divisions and cover most commercial weighing, including retail, shipping, bench and floor scales.
What is the difference between d and e on a scale?
d is the displayed division, the smallest step shown. e is the verification division used for legal-for-trade tolerances. For example, the A&D FX-300iN displays 0.001 g with e = 0.01 g.
Is an NTEP scale legal for trade right out of the box?
The model is approved, but each commercial scale must be installed, calibrated and placed in service by a registered service technician, and it is subject to inspection by state weights and measures officials.
Which scale is legal for trade for gold and jewelry?
Use an NTEP Class II scale such as the A&D EK-1200i (1200 g x 0.1 g, CC 04-019), the A&D FX-200iN or the A&D FX-300iN.