HPC calibration of ultrasonic gas meters is a basic requirement in the lifecycle of these flowmeters, ensuring accuracy and reliability in critical applications, particularly in custody transfer application of natural gas. According to the guidelines of the National Iranian Gas Company and in compliance with IGS-C-IN105, the calibration interval for these meters is defined as 8 years, making the process indispensable for guaranteeing proper performance. Delta Gas Mobin Group, leveraging its technical expertise and established partnerships, provides the possibility of sending ultrasonic flow meters to recognized international calibration laboratories. These laboratories, equipped with advanced facilities and calibration lines capable of replicating real operating conditions, conduct calibrations across a wide range of pressures and flow rates, with results recognized for their highest level of credibility. As these laboratories operate under globally accepted standards and hold internationally recognized accreditations such as ISO/IEC 17025, the issued calibration certificates are widely accepted and referenced in many countries. Upon completion of calibration, results are provided in the form of official certificates fully aligned with international standards and guidelines, including OIML R137, AGA 9, and ISO 17089. This process not only enhances confidence in measurement accuracy but also mitigates the risk of errors and increases customer trust in both commercial and industrial applications. Furthermore, conducting calibration at prescribed intervals extends the service life of the equipment while reducing unnecessary maintenance or replacement costs. Through the provision of such services, Delta Gas Mobin Group assures its clients that their equipment is fully compliant with the highest global standards and is adequately prepared for participation in both national and international projects. Ultimately, the company’s focus on delivering calibration services that are precise, efficient, and reliable plays a vital role in strengthening the country’s position in advanced gas metering technologies and in achieving the strategic development goals of the energy sector.