Checkweigher Scales Guide: How Checkweighing Works and the Best A&D Checkweighers

Checkweighing is one of the fastest ways to catch underfilled packages, missing parts and portion errors before they reach a customer. MNM Scales is an authorized A&D dealer and one of the largest scale distributors in the country, with over 30 years in business. This guide covers static checkweighers, the bench scales an operator loads by hand, and shows how to pick capacity, readability and features.

How a checkweigher scale works

1. Set the limits. Enter a target and a lower and upper limit, or recall them from memory for that product.
2. Place the item. The scale compares the weight with the limits.
3. Read the lights. A&D models use red, green and yellow (or 3-color, 5-step) comparator lights for LO, OK and HI, which are easy to see from across a bench.
4. Act on the result. Add or remove product, or reject the item. Many models can also send the result to a PC, printer or relay for a light tower or buzzer.

Our picks: best checkweigher scales

Scale	Capacity x readability	Highlights	Best for
A&D HT-500CL	510 g x 0.1 g	LED checkweighing lights, carrying case	Small parts, samples and portions
A&D FS-6Ki	6 kg x 0.5 g (15 lb x 0.001 lb)	Stainless steel, IP65, 100 limit memories	Food portions and light packages
A&D FS-15Ki	15 kg x 1 g (35 lb x 0.002 lb)	Stainless steel, IP65, 60-segment analog sweep display	Packaging and food production
A&D FS-30Ki	30 kg x 2 g (70 lb x 0.005 lb)	Larger 380 x 300 mm pan	Cases, bags and bulk portions
A&D HV-15KC	6/15/30 lb x 0.002/0.005/0.01 lb	NTEP, triple range, 3-color 5-step LED comparator	Legal-for-trade checkweighing and counting
A&D HV-60KC	30/60/150 lb x 0.01/0.02/0.05 lb	NTEP, triple range, 13 x 16.7 in platform	Heavier cartons and shipping checks
A&D HV-60KCWP	30/60/150 lb x 0.01/0.02/0.05 lb	NTEP, IP65 washdown	Wet areas and food processing

FS-i readabilities shown are the finest of three user-selectable resolutions. A&D also builds NTEP Class III versions of the FS-i (FS-6KiN, FS-15KiN and FS-30KiN, NTEP CC 07-104); call us to order one. The HV-C models stabilize within about 1 second and run on an AC adapter or, on the HV-15KC and HV-60KC, four D batteries. Need to count parts as well as check them? See our counting scale buying guide.

How to choose a checkweigher

• Capacity: cover the heaviest item plus its tray or box, with some headroom so the load cell is never overloaded.
• Readability: a common rule of thumb is that the scale division should be no more than about one-tenth of your tolerance band. To hold a 50 g package within ±5 g (a 10 g band), pick a scale that reads 1 g or finer.
• Legal for trade: if the scale determines a net weight you print on a label or charge for, it is a commercial device and should be an NTEP model, placed in service under your state rules (see what NTEP means). For in-process checks, a general-purpose checkweigher works well. To weigh, price and label packages in one step, see our deli scale with label printer guide.
• Environment: choose stainless steel and an IP65 rating, like the FS-i or HV-60KCWP, where scales are washed down. Our washdown scale guide explains IP65, IP67 and IP69K ratings.
• Speed and memory: fast stabilization keeps a line moving, and stored target and limit sets make product changeovers quick.
• Outputs: RS-232C, USB or relay outputs connect to a PC, printer or light tower (options may be sold separately, not included).

Checkweighing packaged goods

Weights and measures inspectors test packaged goods with the procedures in NIST Handbook 133: in general, the average net quantity of a lot must be at least the labeled quantity, and individual packages must stay within the allowed variation. Many packers set the checkweigher’s lower limit at or slightly above the labeled weight, and check the scale daily with a certified weight (see calibration weight classes). Shipping cartons? See our best shipping scale guide.

Calibration and service for checkweighers

A checkweigher is only as good as its last calibration, so plan on at least once a year and more often on busy lines (see how often to calibrate). MNM Scales is TDA licensed with registered technicians and calibrates with in-house or NIST-traceable certificates (which certificate do you need?; calibration prices). On-site service in Houston and suburbs is a $295 service call plus $2 per mile round trip, with Dallas, Austin and San Antonio on request, and nationwide mail-in calibration usually takes 1 to 3 business days. Choose the tier by the scale’s maximum capacity:

Frequently asked questions

What is a checkweigher scale?

A checkweigher scale compares an item with preset low and high limits and shows whether it is under, within or over the target, usually with LO, OK and HI lights. It is used for packaging, portion control and parts inspection.

What is the difference between a static and an automatic checkweigher?

A static checkweigher is a bench scale that an operator loads by hand and reads from comparator lights. An automatic (in-motion) checkweigher weighs items on a conveyor and can reject them automatically.

What readability do I need for checkweighing?

A common rule of thumb is a scale division no more than one-tenth of your tolerance band. For a plus or minus 5 g tolerance, choose a scale that reads 1 g or finer.

Does a checkweigher need to be NTEP?

If it determines a net weight printed on a label or used to charge a customer, it is a commercial device and should be an NTEP model placed in service under your state rules. For in-process checks, a general-purpose model works well.

Which A&D checkweigher is waterproof?

The A&D FS-i series (FS-6Ki, FS-15Ki and FS-30Ki) is stainless steel and rated IP65, and the NTEP A&D HV-60KCWP is IP65 washdown rated.

How often should a checkweigher be calibrated?

At least once a year, more often on busy lines, and after a move, overload or failed daily check. MNM Scales offers on-site calibration in Houston and nationwide mail-in calibration, usually in 1 to 3 business days.