Articles about metrology
(Fjernvarmen, October 2005)
Previously calibration of large flow meters (>DN 200) has been problematic as the meters had to be dismantled and sent to an external calibration laboratory. Now it is possible to calibrate meters up to DN 1000 on-site by using a non-contact, optical measurement technique, Laser Doppler Velocimetry (LDV). The flow laboratory at Danish Technological Institute is one of the few laboratories in the world able to offer this accredited service. The article describes the LDV technique illustrated by an example of an on-site calibration of a DN 1000 meter. Examples of application of LDV are also mentioned to provide a better understanding of the flow conditions in pipe systems.
"Laser Doppler Velocmetry (LDV) - An Accredited Method for On-site Calibration of Large Flow Meters", EuroHeat & Power, IV 2005 (English).
This article covers the activities of Danish Technological Institute leading up to the accreditation of the LDV method for on-site calibration of flow meters up to 1000 mm in diameter. The article covers the basics principles of the LDV method, the equipment used, an analysis of the measurement uncertainty, a description of the measurements performed and an outlook for the future use of innovative measurement technique.
Flomeko 2005. The Flow Laboratory at Danish Technological Institute is the only laboratory in the world able to offer accredited on-site calibration of flow meters using Laser Doppler Velocimitry (LDV). This paper presents a new method of calibrating flow meters of 100 to 1000 mm diameter whilst on-site and in operation using LDV. The technique has been tested and demonstrated in the laboratory and in the field. Primarily developed for calibrating district heating meters, the technique is also suitable for measuring flow in other clear fluids. The paper was presented at Flomeko 2005.