The electrical contact level gauge is designed based on the difference in water and vapor resistivity. The electrode of the measuring cylinder has a small impedance to the cylinder in the water. The impedance to the cylinder in the steam is large. As the water level changes, the number of electrodes in the water changes. Converted to a change in resistance value. Transfer to the secondary instrument to achieve water level display, alarm, protection interlock and other functions.
Electrical contact level gauge troubleshooting:
1. The electrode of the electric contact level gauge is prone to be covered by oxide, and its reliability and sensitivity gradually decrease with time. This can be solved by reducing the electrode current of the electrode, because the adsorption force of the electrode is greatly reduced. A pointed electrode can also be used because it has a certain self-cleaning capability, which prolongs the life of the electrode and increases the reliability of the work. In addition, it is also possible to adopt a method of tilt mounting in order to reduce the chance of alarming at the upper and lower limits of the electrode, since it is possible to reduce the probability that the electrode bead communicates with the liquid bead flowing down the container wall. The electric contact level gauge should be drained frequently and flushed with steam to reduce the cover on the electrode contacts and clean the contacts so that the indicator of the secondary meter is not dimmed or misdirected.
2. The upper and lower limit alarm devices of the electric contact level gauge sometimes have very contradictory simultaneous actions, that is, the upper and lower limit alarm indicators of the secondary table of the electric contact level gauge flash simultaneously. Although the actual liquid level heights of the high and low ends are impossible to exist at the same time, they are often occurring on the secondary meter, especially when the liquid level detecting cylinder is re-opened after the discharge of the liquid level detecting cylinder. For example, when the on-site glass level gauge indicates 60% scale, the secondary table level indicator of the control room flashes at both the lower limit of 50% and the upper limit of 75%, indicating that the liquid level is higher than the upper limit. Below the lower limit, obviously this is impossible. The reason for the analysis is as follows: after the liquid level detecting cylinder has just been discharged, the actual glass level gauge indicates that it is below the upper limit (75%) scale, but at this time, the high alarm indicator flashes, indicating that the high alarm circuit has formed a path at this time. This may be caused by short-circuiting of the electrode or disconnection of the outer terminal of the electrode, which is in contact with the outer casing of the test cylinder (common end of the power supply), so the indicator light flashes; or the outer end of the electrode may be dirty and short-circuited with the outer casing of the test cylinder; The loop cable is grounded. Sometimes the high-alarm indicator flashing phenomenon will disappear for a few tens of minutes or so, and it will return to normal, indicating that the high-alarm flash is due to the residual liquid bead on the electrode and the liquid bead flowing down the wall of the detector barrel during discharge, causing errors. Instructions. If the high alarm indicator is still flashing after half an hour, and the actual liquid level is normal, then it should be found according to the above reasons. This high alarm flash is sometimes caused by a false level. Sometimes, in the normal liquid level, after the liquid level detection cylinder is discharged, the lower limit of 5% is flashing, indicating that the circuit has been disconnected, which may cause the external end of the electrode to be broken or not well connected, and the cable lead is broken. The circuit is not well connected to the terminal at the point where the racetrack is controlled; it may also be a problem with the lower limit of the secondary table (50%). Sometimes the false level will also cause a low alarm flash.
Curing Agent
Curing agents, also known as hardeners, are essential components of many polymer systems, including Epoxy Resins. Curing agents react with the epoxy resin to form a three-dimensional crosslinked network, resulting in a cured polymer with improved mechanical properties, chemical resistance, and thermal stability.
There are several types of curing agents, each with its own unique properties and applications. The most common type is amine-based curing agents, which react with the epoxy functional group to form a secondary amine and an alcohol. This reaction is exothermic and can be accelerated by heat, making it ideal for high-temperature applications.
Another type of curing agent is anhydride-based, which react with the epoxy group to form a cyclic acid anhydride and a hydroxyl group. These curing agents are typically used in applications where water resistance is critical, such as marine coatings and adhesives.
Other types of curing agents include phenolic, acid, and catalytic curing agents. Phenolic curing agents are used in high-temperature applications, while acid curing agents are used in low-temperature applications. Catalytic curing agents are used to accelerate the curing process and are typically used in combination with other curing agents.
The choice of curing agent depends on the specific application requirements, such as cure time, cure temperature, and final properties of the cured polymer. It is important to choose the correct curing agent to ensure that the final product meets the desired specifications.
In summary, curing agents are essential components of many polymer systems, including epoxy resins, and play a critical role in improving the mechanical, chemical, and thermal properties of the cured polymer. The choice of curing agent depends on the specific application requirements and must be carefully considered to ensure the final product meets the desired specifications.
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