OIML Accuracy Classes Explained | Load Cell Accuracy OIML Accuracy Classes Explained | Load Cell Accuracy | HBM

OIML accuracy classes explained: Which load cell for which application?

Demands on load cell accuracy vary with the different tasks. For example, an accuracy to the very last gram is only rarely required when weighing building materials such as cement or gravel - here, rougher values are sufficient than, for example, with shop-counter scales or high-precision dosing systems where grams or micrograms are required.

Internationally agreed accuracy classes per OIML R60 provide valuable information for choosing the right load cell for a specific application. All HBM load cells have been classified and tested per OIML R60.

HBM load cells use strain gage technology. These load cells convince through their attractive price, long life and accuracy. In addition, they require little space for mounting and are easy to install.

HBM mainly offers load cells with accuracy classes C3, C3MR and C6. This means that the load cells comply with requirements precisely specified for various factors that are critical to the quality of the measurement result, for example, linearity and temperature behavior.

Which accuracy class for my application?

Here you will find our recommendations for accuracy classes and their suitability for your application. In general, there is a global trend toward ever increasing accuracy. HBM offers load cells with the high accuracy class C6 already today. C6 quality load cells offer excellent properties, particularly for developing new concepts for scales and high-precision checkweighers.

Furthermore, we are continually improving the accuracy of our load cells up to levels that have so far seemed out of reach for load cells using strain gage technology. This opens up many new opportunities for innovative weighing technology activities and products, especially since strain gage load cells are available at substantially lower prices than load cells based on electromagnetic force compensation that are normally used. Get in touch with us.

Typical applications

Load cells with different accuracy classes are required depending on the application. The chart provides an overview of typical applications, ranging from the lowest to the highest accuracy class.

Load cells with relatively low accuracy classified D1 to C2 are sufficient for simple building materials scales used to weigh sand, cement or water.

Adding the right proportion of additives to building materials is essential. For this purpose, special building materials scales using accuracy class C3 load cells are available for mixing additives such as ash or sand . 

Accuracy class C3 load cells are widely used in machine construction as well. Here, scales contribute to quality assurance, for example, when ball bearings are checked.

However, increased accuracy is needed with shop-counter scales or scales used in filling machines. Grams or micrograms are required here. Load cells used in these applications comply with accuracy classes C3 to C6.

At present, load cells integrated in special shop-counter scales or also in checkweighers attain the highest accuracy class C6. These mostly dynamic checkweighers enable highly precise production monitoring of goods based on weight criteria. Food packaging is a typical example application.