Electrical/visual differential pressure indicator with solid state sensor

Abstract

A method of determining fouling of a filter includes the use of a differential pressure indicator which has a housing with at least two ports in the housing. One port receives a first pressure, and the second port receives a second pressure. A pressure resistive device is placed between the first port and the second port, and changes its position when the first pressure exceeds the second pressure by a predetermined amount. A magnet is coupled to the pressure resistive device. A digital displacement sensor senses the position of the magnet and is in communication with an electronic indicator. The electronic indicator activates when the first pressure exceeds the second pressure by a predetermined amount, thus allowing determination of filter fouling.

What is claimed is:  
     
         1 . A method of determining a fouling status of a filter, comprising: 
 measuring a differential pressure between a flow upstream from the filter and a flow downstream from the filter;    causing, by means of a solid state digital displacement sensor, an electronic indicator to activate when the differential pressure is higher than a set value; and    determining the fouling status of the filter based on the activation of said electronic indicator.    
     
     
         2 . The method of  claim 1 , wherein the electronic indicator is a light emitting diode (LED).  
     
     
         3 . The method of  claim 1 , wherein the electronic indicator is an auditory alert.  
     
     
         4 . The method of  claim 1 , wherein said differential pressure is measured by a measurement device comprising: 
 a housing having a first port to which the upstream flow pressure is ported and a second port to which the downstream flow pressure is ported;    a pressure resistive device located between the first port and the second port, wherein the pressure resistive device changes its position when the upstream pressure exceeds the downstream pressure by a predetermined amount; and    a magnet coupled to the pressure resistive device.    
     
     
         5 . The method of  claim 4 , wherein the electronic indicator is activated based on a position of the magnet as detected by the solid state digital displacement sensor.  
     
     
         6 . The method of  claim 4 , wherein the electronic indicator is located remotely from the housing of the measurement device.  
     
     
         7 . The method of  claim 4 , wherein the measurement device further comprises a control module, said module being electrically coupled to the solid state digital displacement sensor and in communication with the electronic indicator, said electronic indicator being activated based on a position of the magnet as detected by the solid state digital displacement sensor.  
     
     
         8 . The method of  claim 7 , wherein the control module is an electronic circuit.  
     
     
         9 . The method of  claim 7 , wherein the control module is a microcontroller.  
     
     
         10 . The method of  claim 9 , wherein the measurement device includes a plurality of electronic indicators sequentially activating according to a schema based on temporal measurements of signals from the solid state digital displacement sensor.  
     
     
         11 . The method of  claim 4 , wherein the pressure resistive device includes a piston assembly having a piston and a spring coupled to a first end of the piston, said magnet being coupled to a second end of the piston.  
     
     
         12 . The method of  claim 4 , wherein the pressure resistive device includes a diaphragm assembly having a diaphragm and a connecting rod, wherein a spring is coupled to a first end of the connecting rod and the magnet is coupled to a second end of the connecting rod, and the connecting rod is coupled to the diaphragm at a location between the first end and the second end of the connecting rod.  
     
     
         13 . A method of determining a fouling status of a filter, comprising: 
 (a) measuring a differential pressure between a flow upstream from the filter and a flow downstream from the filter;    (b) causing, by means of a solid state digital displacement sensor, a plurality of electronic indicators to become sequentially activated at predetermined intervals when the differential pressure is higher than a set value;    (c) correlating said intervals to the amount of time for which said differential pressure remains higher than said set value; and    (d) determining the fouling status of the filter based on the number of said plurality of electronic indicators that are activated.    
     
     
         14 . The method of  claim 13 , wherein the electronic indicator is a light emitting diode (LED).  
     
     
         15 . The method of  claim 13 , wherein the electronic indicator is an auditory alert.  
     
     
         16 . The method of  claim 13 , wherein the electronic indicator is located remotely from the filter.