Abstract: A method for monitoring exposure time of workers involves the use of a sensor, which is carried by the workers for monitoring continually in a real-time fashion in an environment such that the results are recorded by a recorder. The an add-on or built-in timer in the sensor or the recorder is used to monitor time, which is recorded in the recorder simultaneously, so as to obtain the real-time continuous exposure level of a hazardous material in the environment.

Abstract: A method for monitoring exposure time of workers involves the use of a sensor, which is carried by the workers for monitoring continually in a real-time fashion in an environment such that the results are recorded by a recorder. The an add-on or built-in timer in the sensor or the recorder is used to monitor time, which is recorded in the recorder simultaneously, so as to obtain the real-time continuous exposure level of a hazardous material in the environment.

Abstract: A device is used to monitor a worker's exposure to a hazardous gas in a workplace. The device includes an infrared locating member, a chemical sensor, a controller, and a power source. The infrared locating member is used to monitor the worker's exposure position. The chemical sensor is uses to monitor the worker's exposure concentration. The controller serves as a central processing unit to receive an exposure position signal from the infrared locating member, and an exposure concentration signal from the chemical sensor. The controller is provided with a built-in or externally-connected timer.

Abstract: A device is intended to measure an absorbed dose of a hazardous gas by skin of a human body and is composed of an exposure chamber, a gas concentration control system, and one or more gas sensors. A naked part of the human body is held in the exposure chamber containing the hazardous gas of a concentration which is kept in a predetermined range by the gas concentration control system. As the concentration of the hazardous gas drops below the predetermined range, the gas concentration control system replenishes the exposure chamber with an amount of the hazardous gas with the help of a concentration signal transmitted from the sensors, so that the concentration of the hazardous gas is once again kept in the predetermined range. The absorbed dose of the hazardous gas by skin is computed on the basis of the amount of the hazardous gas that is replenished.

Abstract: Methods and apparatus for the continuous monitoring of ambient particulate mass in a gas sample encompassing the monitoring of PM.sub.10, (particulate matter greater than 10 .mu.m) and coarse particles (2.5 to 10 .mu.m), the determination of the size distribution of particles, the determination of particle density and the determination of particle-bound water, utilizing such laboratory equipment as an inertial impactor, a virtual impactor, diffusion dryer(s), HEPA filter(s), particulate matter collector(s), and pressure transducer(s).

Abstract: Apparatus for measuring the amount of particulate matter in a gas having a gas supply, a first particulate matter collector downstream of the gas supply and in gaseous communication with the gas supply, and a second particulate matter collector downstream of the gas supply and in gaseous communication with the gas supply. Gas from the gas supply to the second particular matter collector is passed through a particle remover to remove particulate matter prior to contact of gas from the gas supply with the second particulate matter collector. A pressure sensor is provided to measure differential pressure between the first particulate matter collector and the second particulate matter collector, and at least one pump to cause gas to pass from the gas supply to the first particulate matter collector and the second particulate matter collector.