Monitoring system for a liquid purification system
US4806912A · kind A · utility
Inventor
Key dates
| Filing date | Jun 19, 1987 |
| Grant date | Feb 21, 1989 |
| Priority date | — |
| Expiry date | Jun 19, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D61/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A system for monitoring the operation of a water purification system of the type having an inline membrane includes a first conductivity measurement cell located upline of the membrane and a second conductivity measurement cell located downline of the membrane. The cells are electrically connected in series and across the output of a symmetrical square wave generator. A differential amplifier compares the voltage across one of the cells with a predetermined reference voltage to develop a control signal when the conductivity of downline cell relative to the upline cell rises above a predetermined threshold level. An output circuit responsive to this signal drives an appropriate one of two indicator lamps to indicate satisfactory or unsatisfactory system operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.