Calibration of a Two-Color Imaging Pyrometer and Its Use for Particle Measurements in Controlled Air Plasma Spray Experiments

Published

June 1, 2002

Author(s)

Steven P. Mates, D Basak, Frank S. Biancaniello, Stephen D. Ridder, Jon C. Geist

Abstract

Advances in digital imaging technology have enabled the development of sensors that can measure the temperature and velocity of individual spray particles over a large volume of the spray plume simultaneously using imaging pyrometry (IP) and particle streak velocimetry (PSV). This paper describes calibration, uncertainty analysis, and particle measurements with a commercial IP-PSV sensor designed for measuring particles in an air plasma spray (APS) process. Yttria-stabilized zirconia (YSZ) and molybdenum powders were sprayed in the experiments. An energy balance model of the spray torch was used to manipulate the average particle velocity and temperature in desired ways to test the response of the sensor to changes in the spray characteristics. Time-resolved particle data were obtained by averaging particle streaks in each successive image acquired by the sensor. Frame average particle velocity and temperature were found to fluctuate by 10 % during 6 s acquisition periods. These fluctuations, caused by some combination of arc instability, burbulence and unsteady powder feeding, contribute substantially to the overall particle variability in the spray plume.

Citation

Journal of Thermal Spray Technology

Volume

11

Issue

No. 2

Pub Type

Journals

Keywords

air plasma spray, calibration control, imaging pyrometry, particle sensor

Citation

Mates, S. , Basak, D. , Biancaniello, F. , Ridder, S. and Geist, J. (2002), Calibration of a Two-Color Imaging Pyrometer and Its Use for Particle Measurements in Controlled Air Plasma Spray Experiments, Journal of Thermal Spray Technology (Accessed October 14, 2025)