Detection of toluene diisocyanate in air with a coated piezoelectric crystal: Part 2. Development of an Instrumental Method For Personal Monitoring

Gases in the atmosphere are monitored with chemically-coated quartz piezoelectric crystals; the method is demonstrated in the use of polyethylene glycol for toluene diisocyanate determination. A microprocessor is used to control the gas sample flow through the detector head as well as the data acquisition. A computer-based procedure for data treatment permits signal integration and background drift correction, resulting in a theoretical detection limit of about 0.006 ppm. The design of a basic portable instrument for piezoelectric crystal monitoring of toxic gas is described with a view to future modification and microprocessor control.