Method of sensing contamination in the atmosphere

Claim 2

A continuous method of sensing contamination in the atmosphere in which the rate of change of frequency of an unsealed dual mode quartz crystal resonator is used to measure the rate of change of contamination induced by the adsorption of contaminant molecules, said method including the steps of: (A) cleaning the electrodes of the resonator, (B) allowing contamination from the atmosphere to be adsorbed onto the resonator and simultaneously measuring the rate of change of frequency to measure the rate of change of contamination until nearly a monolayer compensating for temperature induced frequency shifts, and (C) repeating steps (A) and (B).

Claim 3

Method according to claim 1 where steps (A) and (B) are continuously repeated until it is no longer desired to sense the contamination in the atmosphere.

Claim 4

Method according to claim 1 wherein step (B) is carried out until 75 percent of a monolayer of contamination is adsorbed onto the resonator.

Claim 5

Method according to claim 1 wherein the electrodes are cleaned by the use of UV-ozone.

Claim 6

Method according to claim 1 wherein the method is used to sense toxic gas in the atmosphere.

Claim 7

Method according to claim 1 wherein the unsealed dual mode resonator is a 10 megahertz third overtone SC-cut resonator.

Claim 8

Method according to claim 1 wherein the electrodes are gold.

Claim 9

Method according to claim 1 wherein the electrodes are carbon.

Claim 10

Method according to claim 1 wherein the electrodes are selective for a particular contaminant.

Claim 11

A continuous method of sensing contamination in the atmosphere in which the rate of changes of frequency of multiple unsealed dual mode quartz crystal resonators, each with a different set of electrode surfaces, are used to measure the rate of change of contamination induced by the adsorption of contaminant molecules, said method including the steps of: (A) cleaning the electrodes of the resonators, (B) allowing contamination from the atmosphere to be adsorbed onto the resonators and simultaneously measuring the rate of change of frequency to measure the rate of change of contamination until nearly a monolayer of contamination has been adsorbed onto the resonators while compensating for temperature induced frequency shifts, and (C) repeating steps (A) and (B).

Claim 12

A continuous method of sensing contamination in the atmosphere in which the rate of changes of frequency of multiple unsealed dual mode quartz crystal resonators, each with a different set of electrode surfaces, are used to measure the rate of change of contamination induced by the adsorption of contaminant molecules, said method including the steps of: (A) cleaning the electrodes of the resonators, (B) allowing contamination from the atmosphere to be adsorbed onto the resonators and simultaneously measuring the rate of change of frequency to measure the rate of change of contamination until nearly a monolayer of contamination has been adsorbed onto the resonators while compensating for temperature induced frequency shifts, and (C) repeating steps (A) and (B).

Claim 13

Method according to claim 10 wherein the multiple unsealed resonators are a set of discrete resonators.

Claim 14

Method according to claim 10 wherein the multiple unsealed resonators are a single quartz substrate with multiple sets of electrodes on it.

Claim 15

Method according to claim 10 wherein the variations in frequency changes due to the desorbing-actions of UV-ozone are used to identify the contaminant gases.

Claim 16

Method according to claim 10 wherein a particle filter is included to filter out UV-ozone resistant contaminants.