Fluid pressure and velocity sensing apparatus
US4311436A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 13, 1979 |
| Grant date | Jan 19, 1982 |
| Priority date | — |
| Expiry date | Nov 13, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2202/02
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Apparatus for measuring fluid pressure and velocity, and in particular for maintaining an aspirator air velocity constant under varying atmospheric conditions. A precisely controlled air velocity is provided by a reference air source whose frequency is derived from a crystal oscillator. The total air pressure from the aspirator wind tunnel is compared with the total air pressure from the reference air source using a matched thermistor pair technique to convert the pressure difference into an electrical error signal which is used to control the main air source for the aspirator wind tunnel such that the error signal is maintained at zero, thereby maintaining the air velocity in the aspirator constant.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.