ASSESSMENT OF OPACIMETER CALIBRATION ON KRAFT PULP-MILLS

This paper describes the methodology and specific techniques for calib rating automatic on-line industrial emission analysers, specifically e quipments that measure total suspended dust installed in pulp mills wi thin the scope of Portuguese Regulation No. 286/93 on air quality. The calibration of opacimeters is a multi-parameter relationship instead of the bidimensional calibration which is used in industrial practice. For a stationary source from a pulp mill such as the recovery boiler stack, which is subjected to significant variations, the effects of pa rameters such as the humidity and gas temperature, deviations of isoki netism, size range of particles and characteristic transmittance of eq uipment are analysed. The multivariable analysis of a considerable set of data leads to an estimate of about 98% of equipment transmittance over the other parameters with a level of significance greater than 0. 99 which is a validation of the bidimensional practical calibrations. (C) 1998 Elsevier Science Ltd. All rights reserved.