Have you ever looked at an NTEP-certified scale and wondered what the d and e values signify? Understanding these scale values is important for making sure a specific scale is certified to use for an application. Our goal in this guide is to demystify the scale buying experience and to make your purchasing process much more straightforward. So, let’s get into why these e and d values are important and how you can use them to determine the right NTEP-certified scale for your application.
UNDERSTANDING D VALUES
D values represent a scale’s standard division size. The value of scale division “d” expressed in a unit of weight, is the difference between two consecutively indicated values for digital indication. The D value is equal to:
- 1, 2, 5; or
- A decimal multiple or submultiple of 1, 2, or 5 (i.e., 10, 20, 50, 100; or 0.01, 0.02, 0.05; or 0.1, 0.2, 0.5, etc.); or
- A binary submultiple or a specific unit of weight (i.e., ½, ¼, 1/8, or 1/16).
The d value measures the accuracy of your scale by indicating the scale capacity divided by the increment size. It refers to the value of scale division or the level of accuracy or inaccuracy your scale is reading at.
D values represent the smallest standard displayed division of the scale and are not used legally for trade applications in most states.
UNDERSTANDING E VALUES
E values provide similar information to d values, just at a more accurate level. E values are more precise, indicating the verification scale division. Essentially, it’s the value of scale that’s trade-approved, as specified by the manufacturer, which determines the tolerance values and accuracy class applicable to the device. It represents the legal-for-trade verification division or certified readability.
In many cases, both the d value and the e value will be the same. In every case, the e value must be greater than or equal to the d value. For example, for Class I and Class II balances, if e does not equal d, then e must be equal to or greater than ten times d.
The e value is not required to be marked on a scale if it equals the d value, and since the two values are usually equal, scales typically don’t designate the e value.
USING SCALE VALUES TO DETERMINE THE RIGHT SCALE FOR AN APPLIACTION
If you’re looking for the e-value to verify that a specific NTEP-certified scale will work for an application, we recommend you visit the NTEP Certificates of Conformance Database. There, you’ll find NTEP certificates of scale based on:
- Certificate number
- Device type
Each certificate will provide an approval table that will display the value of scale for each device in the device family. For example, the Ohaus SJX certificate has a table that shows the capacity, e value, d value, and other pertinent data for each model in the series.
VERIFY STATE LAWS FOR SCALE VALUES
The last thing you’ll need to do before purchasing a scale is to verify any applicable state laws for scale values. Some states require different classes of NTEP scales for specific applications, so it's important to determine what those values are before purchasing a scale.
For instance, prescription-filling or cannabis use cases both tend to have different specifications by state, so be sure to do your research before buying.
You can find more information about particular state laws regarding scale values by contacting your local Department of Weights and Measures or by reaching out to the experts at Scales Plus.
DETERMINING THE RIGHT NTEP-CERTIFIED SCALE FOR YOUR APPLICATION
At Scales Plus, we understand the importance of identifying the right scale for your application. As an authorized dealer, we'll support you throughout the entire scale purchasing process, and our knowledgeable staff will ensure you're choosing a high-quality scale that's compliant and suited for your application. Reach out to get the conversation started, or check out our selection of scales if you’re ready to purchase.