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Weights and Measures


Commercially used scales must be reliable, accurate, and be designed, used, and maintained in a manner that fosters trust and confidence in the device. 

First Steps​​​

​B​efore a scale may be used commercially in Oregon it must be properly "licensed" and "placed in service".


​A commercial scale is licensed once you complete the license application and submit payment of the license fees to ODA.

Placing a scale into service

A commercial scale is placed into service when the following actions are completed: 

1. The scale is evaluated for conformance to the specifications and tolerances found in NIST Handbook 44.

    • ​A scale meets the specifications if it has a National Type Evaluation Certificate.  The certificate number is a 5 digit hyphenated number located on a permanent label on your scale (examples: 00-000, 00-000A1, 00-000A2, etc.)
    • ​Proving that a scale meets the required tolerance means testing it with known test weights.  Scales can easily lose calibration during shipping so its best to test it upon initial setup.  If you don't have the equipment a service agent can assist you with this task.
​2. A placed in service report is completed and returned to the ODA Weights and Measures Program.

Once payment of the license is made and the placed in service report is submitted you may legally use your scale in commerce. 


Weights and Measures Forms

License Application and Placed in Service (PISR) Forms Weights and Measures Forms


Initial Followup

Once your paperwork is received an ODA weights and measures inspector will be assigned to your scale.  Once received the inspector will meet with you to verify that it meets all requirements of a legal for trade scale.  Once the initial verification is completed and the scale is approved the inspector may return annually to conduct a reevaluation of the scale.

Continued Use of the Scale


You are responsible for ensuring that your commercial scale: 
  • is used in the manner intended by the manufacturer.
  • is suitable for each transaction.
  • is installed appropriately to ensure consistent and reliable weighing.
  • is maintained and remains In good repair​.
  • is accurate at all times.

Scale Positioning

If the scale is used in direct sales then it must be positioned so that all parties to the transaction present may witness the weighing process and view the display.  The customer must be able to view the process and the indicator from a normal customer postion without asking for permission.  

For example if the customer is normally on one side of a counter and the vendor on the other then the indicator must be positioned so that both parties can see it from these respective postions, you may may not require that the customer come behind the counter to see the weighing process.  An auxillery indicator may be used to help satisfy this requirement. 

Packaging and tare

Commercial scales are often used to certify package weights.  Package weights statement must be net weight, not gross weight.  The net weight statement must reflect the weight of the product contained inside the package less the weight of any packaging materials used solely to contain and protect the product during transportation.  

The weight of the packing materials is the "tare weight" or "tare" for short. 

Many scales provide automatic tare functions for certain products. You can verify that the automatic tare is correctly taken by first placing the empty container onto the scale and verifying that the scale reads zero before filling the container.

Rejected scales​​

It is your obligation to maintain your scale in good working order as a condition of using it in commercial service (ref: ORS 618.081).  If an issue is identified during a routine inspection by your weights and measures inspector then the scale is formally "rejected" as being "incorrect" and a repair order will be issued with instructions on how to correct the deficiency.  Depending on the nature of the deficiency the scale may be ordered out of service immediately or you may be granted a grace period where you may continue use of the scale while you arrange for repairs.

ODA tracks the repair and stop use orders (blue and red tags) to ensure that the problem is remedied in an acceptable manner understanding that it is unlawful to use a scale which has been rejected beyond the allowed grace period.  An extension for the grace period may be made by contacting your inspector (for inspector contact information please see your scale test report).

You may resume use the scale once the following tasks are complete:

  1. The deficiency is corrected (i.e. the scale was recalibrated, the scale was cleaned of interfering debris, the security seal was installed, the scale was replaced, etc.)
  2. The blue or red rejection tag is completed and returned to ODA per the instructions on this form.  A placed in service report may be returned in lieu of a lost or damaged tag; Please inclu​​​de the tag number in the place in service reports which may be found on your most recent inspection report.
​Your weights and measures inspector will be notified and may return to verify that the repair was completed.

Service/Repair companies

Service companies are often able to help you with the following:

  • Purchase an NTEP approved legal for trade weighing or measuring device which will meet the legal requirements for a commercial scale in Oregon.
  • Assist you in placing a commercial scale into service.
  • Calibrating and sealing a commercial weighing or measuring device.
  • Servicing your commercial scale.
When contacting a service company we recommend that you ask them if they are familiar with Oregon's weights and measures laws and whether or not they can help you complete the required placed-in-service report forms.

NOTE: There are a lot of choices when shopping for a commercial scale.  When considering the overall costs we advise that you keep the additional service costs such as the initial calibration and ongoing service expenses in mind while selecting a supplier.  A supplier with the capability to provide you with local service may be a better value in the long run.
NOTE: ODA does not recommend any service companies.  ​

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Main Office
Weights and Measures
635 Capitol St NE
Salem, OR 97301
Phone: 503-986-4670