REFRACTOMETER ADSORPTION IN TRANSIENTS AND AT SUB-FREEZING TEMPERATURES.
Abstract
This work extends the investigation of the refractometer response to humid air in four directions. The observed magnitude of adsorption error in the h-f refractometer at temperatures down to -23C remains large for relative humidities above 90 percent, increasing to 150 N-units as humidity approaches saturation; no adsorption error is found in the dual-cavity refractometer at temperatures -13C for humidities up to 85 percent, but further work must be preceeded by a study of the stability of the refractometer calibration. The magnitude of smoothness of the surface and absence of chemical contamination are important factors in reducing adsorption effects. The response of the h-f refractometer to a transient in air refractivity depends upon the speed of the sensor through the transient and upon the air humidity; at low humidities the refractometer responds faithfully to the transient, but at high humidities, the indicated amplitude decreases with increasing speed of the sensor; recovery of the instrument after passage through the transient is extended with increasing exposure time in the jet and with increasing jet humidity. The thermal lag of the h-f refractometer is complicated by the instrument geometry; a detailed analysis of this property of the instrument is recommended. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1968
- Accession Number
- AD0679998
Entities
People
- Donald R. Hay
Organizations
- Western University