How to secure reference outcomes in span calibration

Achieving precise and reliable weighing measurements with balances and scales is critical to maintaining operational efficiency and regulatory compliance across a number of industries. In this respect, span calibration is a crucial process that ensures weighing instruments perform accurately across their full range.

While routine internal checks can help maintain accuracy, professional calibration is sometimes necessary to meet industry standards and ensure traceability to recognised benchmarks. By following a structured calibration approach, whether in-house or through certified professionals, businesses can enhance measurement consistency and avoid errors that could impact product quality and process integrity.

What is span calibration?

Span calibration is a process used to verify and adjust the accuracy of weighing instruments and sensors like balances and scales. It involves testing the device with a known reference weight at the upper limit of its measuring range to confirm that readings remain within acceptable tolerances. Proper span calibration ensures consistency, reliability and compliance with industry standards such as ISO 9001 and ISO 17025. 

Step-by-step guide to secure reference outcomes with span calibration

1. Establish a controlled environment

Environmental factors such as temperature, humidity, air pressure and vibration can influence calibration accuracy. Ensure that the calibration area is stable and free from external disturbances.

2. Select the correct reference weights

Using traceable reference weights that comply with national and international calibration standards is essential. Weights should be certified and regularly verified to maintain their accuracy.

3. Perform zero calibration

Before conducting span calibration, set the instrument to zero with no load applied. This eliminates baseline errors and ensures that all measurements begin from an accurate starting point.

4. Apply reference weights systematically

Place the certified reference weight on the weighing instrument, ensuring it is correctly positioned. Record the displayed measurement and compare it to the expected value.

5. Adjust calibration settings

If discrepancies exist between the measured value and the reference weight, adjust the instrument’s calibration settings according to the manufacturer’s guidelines. Most weighing systems have a built-in span calibration function that allows for fine-tuning.

6. Validate repeatability

To confirm accuracy, repeat the span calibration process multiple times. Record the outcomes to ensure consistency and identify any potential deviations.

7. Document calibration results

Maintaining accurate calibration records is crucial for compliance and traceability. Document each calibration session, including the date, reference weights used, environmental conditions and any adjustments made.

Cases where professional calibration is needed for optimal accuracy

In situations where extreme accuracy and precision are required, laboratory calibration or mobile calibration by professionals may be essential. Some industries, such as pharmaceuticals, aerospace and high-precision manufacturing, operate under stringent regulations where even the slightest deviation in measurement can have significant consequences.

Laboratory calibration

Laboratory calibration is conducted in a controlled environment with highly specialised equipment, eliminating external variables such as temperature and humidity fluctuations. This method ensures the highest level of accuracy and provides detailed calibration certificates traceable to national and international standards. It is particularly necessary for highly sensitive instruments or those used in critical applications.

Mobile calibration

For businesses requiring minimal downtime, mobile calibration services offer a convenient alternative without compromising on accuracy. Professional calibration teams bring accredited equipment and expertise directly to the operational site, allowing for precise adjustments in real-world conditions. This method is ideal for industries that require regular calibration but cannot afford to remove instruments from service for extended periods.

Ensuring long-term accuracy and compliance with industry-leading calibration

Achieving accurate span calibration results is essential for operational efficiency and regulatory compliance. For businesses that require the highest level of calibration accuracy, working with a trusted partner like DM ensures full traceability and compliance with industry standards. 

Our expert team provides both laboratory and mobile UKAS accredited calibration solutions tailored to your needs. To learn more about the importance of traceable calibration and how it can benefit your operations, download our comprehensive guide today.