Gas measuring and warning device with indicator tube through which gas to be tested is directed
US4245997A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 9, 1979 |
| Grant date | Jan 20, 1981 |
| Priority date | — |
| Expiry date | Mar 9, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N31/223
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device and method for measuring the concentration of a gas carried in a medium such as air comprising, an indicator tube having material therein which progressively changes color along its length as it is exposed to the gas to be measured. A flow device is connected to the indicator tube for drawing or pushing the carrier with gas therethrough to cause the progressive change in color in the indicator tube material. A light barrier in the form of a light source and detector facing each other and on either side of the indicator tube is provided and mounted to slide along the axis of the indicator tube and in a direction of propagation of the progressive color change. A reference light barrier is provided in the area of the indicator tube which is not exposed to the progressive color change to produce a reference signal which is compared to a signal produced by the movable light barrier. A motor is connected to the slide mounting of the light barrier for moving it along the axis of the indicator tube and a control device is connected to the movable light barrier, the reference light barrier and the motor for maintaining the movable light barrier in the area of progressive color chan…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.