Weight Certification and Sales - Alpha-Liberty Company

Weight calibration and certificate

Alpha Liberty offers weight verification and certification of analytical weights and weight sets. Calibration weights and weight sets should be re-certified on a managed periodic basis determined by several factors, including environment, frequency of use, demands of the process, quality of the weighing device, age of the weights, and handling during use.

Alpha-Liberty’s mass standards calibration laboratory is designed and constructed to meet the recommended environmental and procedural practices as detailed in National Metrology Institute (NIST) and ISO/IEC standards for the calibration of mass. Our calibration capabilities range from Class 1 to Class F, and from 1 mg to 25 kg. Our lab has been accredited to ISO/IEC 17025:2017 for mass calibration by ANAB.

To accurately estimate the cost of our calibration services, please contact our lab.

Certification documentation

Alpha-Liberty offers accredited weight documentation. Our Weight Calibration Certificate meets requirements of ISO/IEC 17025 and measurements are traceable to the SI through NIST.

The Weight Calibration Certificate lists the uncertainty of the measurement process as it relates to the item being calibrated, lists the actual mass values or the corrections to the nominal mass of the weight being calibrated, and includes the environmental conditions present at the time of calibration.

Certified weight sales

Alpha-Liberty sells a wide selection of quality calibration weights for various applications. The selection of test weights depends on the degree of accuracy needed to satisfy your specific process tolerance. Our friendly customer service staff will help you find just what you need.

To make a recommendation for you, we need some information on the weighing instrument you are using, and the specific weighing tasks being performed, including:

  • Maximum capacity of the weighing device
  • Smallest net weight
  • Weighing tolerance (%)
Contact us and we will customize the correct weight set to fit your specific application. Calibration weights and weight sets include our accredited Weight Calibration Certificate.

Weight handling

Weights are the most frequently used and most important equipment for testing scales and balances. For this reason, weights must be handled carefully. How you handle, clean, and store test weights effects the ongoing accuracy of your weighing processes.

In order to ensure the accuracy of test weights, weights should be stored in original packaging or secure weight cases near the balance. Weights should never be touched with bare hands but should be moved with special tweezers or gloves. All weights should be periodically calibrated and re-certified.

Alpha-Liberty offers a range of accessories for professional weight handling and storage, including tweezers, weight grips, gloves, and a variety of weight cases.

Packaging weights for shipment

It is important that your calibration weights arrive at our lab undamaged. To pack your weights safely, follow these steps:

  1. Secure your weights. Single weights should be individually wrapped. Weight sets need to be secure within their case. All weights need to be secure in a container designed to withstand the shipping process.
  2. Use proper packing material. Single weights should be packaged individually in a vial, pouch, or wrapped in plastic and then bubble wrap or foam. Weight case sets should be put in a plastic bag and wrapped in bubble wrap or foam. [Note: do not use packing peanuts as they create static.]
  3. Separate heavy weights. Large weights (20 pounds and 10 kg) should be packaged in individual boxes.
  4. Include a copy of your purchase order with specific instructions for next calibration due date and return shipping information.
  5. Ensure the shipping box is reinforced and secured with tape, especially on the bottom side of the box.