Apparatus for analysis of aerosols
There is provided apparatus for the measurement of particle mass concentration of an aerosol and which comprises at least one aerosol inlet and at least one electrostatic precipitator which directs an aerosol flow towards a mass sensor on which the particles are collected, the sensor being housed in a magazine including a plurality of other sensors, each of which may be substituted for the sensor, and a control. The control selectively connects one of the at least one aerosol inlet with one of the sensors.
1. Apparatus for the analysis of particles in an aerosol, comprising:
at least one aerosol inlet and at least one electrostatic precipitator which directs an aerosol flow onto a mass sensor on which the particles are collected, the sensor being housed in a magazine including a plurality of other sensors each of which may be substituted for said sensor, and a control, said control selectively connecting one of said at least one aerosol inlet with one of said sensors.
2. Apparatus as claimed in claim 1 wherein each precipitator is mounted in an aperture in a support, and the magazine is movably mounted on the support so that sensors housed in the magazine may each be brought separately into alignment with the precipitator.
3. Apparatus as claimed in claim 2 wherein the magazine is in the form of a carousel and each sensor is aligned with a respective precipitator by indexing the carousel relative to the support.
4. Apparatus as claimed in claim 3 wherein the carousel, is rotatably mounted in a cylindrical recess in the support and is indexed by a motor operated by said control means.
5. Apparatus as claimed in claim 1 wherein the sensor is provided with a heater which is controllable to vary the temperature of the sensor which may be preset to any temperature as is desired.
6. Apparatus as claimed in claim 5 wherein sensor heater controls and mass monitoring controls are housed within the magazine.
7. Apparatus as claimed in claim 1 wherein said at least one precipitator has an inlet provided with a heater which is controllable to vary the inlet temperature.
8. Apparatus as claimed in claim 1 wherein the mass sensor is a piezoelectric quartz crystal.
9. Apparatus as claimed in claim 1 wherein said at least one sensor comprises at least two precipitators each being aligned with a respective sensor.
10. Apparatus as claimed in claim 9 wherein the respective inlets of said precipitators differ one from the other.
11. Apparatus as claimed in claim 10 wherein the inlets have different aerosol size classification properties.
12. Apparatus as claimed in claim 10 wherein one of said inlets is provided with a particle removal system.
13. Apparatus as claimed in claim 1 wherein said at least one aerosol inlet comprises a plurality of aerosol inlets.
14. Apparatus as claimed in claim 13 including a valve assembly, said valve assembly selectively connecting particular ones of said aerosol inlets with certain ones of the sensors.
15. Apparatus as claimed in claim 14 wherein said valve assembly comprises a rotary valve assembly.
16. Apparatus as claimed in claim 15 including an actuator for selectively rotating said rotary valve assembly.
17. A method of analyzing particle mass concentration of an aerosol which includes the use of apparatus as claimed in claim 1 .
18. Apparatus for the analysis of particles in an aerosol and which comprises at least one electrostatic precipitator which directs an aerosol flow onto a mass sensor on which the particles are collected, the sensor being housed in a magazine including a plurality of other sensors each of which may be substituted for said sensor, and control means for automatically operating the magazine to effect a change of sensor.