Intelligent Two-color Electrical Contact Level Gauge Fault Detection and Analysis

 

In the liquid level measurement , the intelligent two-color electrical contact level gauge is widely used due to its wide application range and low maintenance. Electric contact electrodes using different gauge of steam, water or other conductive liquid conductive properties, to measure and display the level of the device under test. Electrical contact level gauges generally consist of a liquid level measurement cartridge and a secondary display. Some electrical contacts in the actual application of liquid level gauge on the device to set aside the electrode mounting position or direct plug-in electrode mounting method for the open device; while the secondary display device is composed of a simple low-voltage transformer and indicator. Electrical contact level gauges also have some problems in practical applications . The following is illustrated by several examples.

 

When the electrical contact is immersed in the liquid, since the liquid resistivity is small, the two electrodes of the electrical contact pass through the liquid, and the voltage drop of the AC signal flowing through the electrical contact is small, so the signal voltage obtained on the detection unit is relatively large, and the display circuit is in phase Turn on, output positive voltage, green LED is on. At this time, the display circuit outputs a +5V signal at the same time as the input alarm contact signal of the logic control circuit.

 

Firstly, the input level transmitter should be cleaned at least once or twice per month. When cleaning, turn on the cap of the input level meter's iron pipe and carefully take out the level gauge; then attach the attached debris on the level gauge (such as Water grass, plankton, etc.) Clear away. Then clean the water level gauge pressure hole, use the trichloroethylene or alcohol injection pressure hole to soak at the height of one-half for about 5 minutes, and then slightly shaken and repeated several times until it is cleaned. It is forbidden to use any appliance to clean the pressure-reducing holes so as not to damage the sensitive core pressure-sensitive diaphragm. Secondly, when cleaning the pressure transmitter of the liquid level transmitter and the pressure-reducing hole, avoid using brushes or metal tools with excessive hardness to avoid damaging the sensitive core and the pressure interface threads. Finally, after the cleaning is completed, the level gauge is slowly put back into the iron pipe, and the lower part of the iron pipe is placed, and the cap can be installed back to the original place. When using, the cable must be connected to the atmosphere and must not be folded straight. There must be no liquid entry or blockage in the ventilation duct. Hope to help everyone.