What Is an Electrode Holder?
An electrode holder is a component that holds the electrodes of an electrode type level switch. An electrode level switch is an industrial device that senses the height of liquid in a liquid storage tank and opens and closes electrical contacts.
Several electrode rods with a weak voltage applied are pointed at the tank, and when they come in contact with the liquid, the electrodes conduct each other to sense the level. Due to the mechanism of the level switch described above, the electrode rods must be insulated from each other when they are not in contact with the liquid.
The electrode holder is a component that holds the electrodes in place while insulating them. The electrode holder has terminals on which the electrode rods and wiring are connected. Depending on the number of electrode rods used in a level switch, products are available that support 3 to 5 electrode rods.
When electrode rods are long, the electrodes may deform and contact each other due to their own weight or the viscosity of the liquid. Separators that hold electrodes apart from each other are also sold as contact-prevention components for long electrodes.
Applications of Electrode Holders
Electrode holders are used as a set of floatless switches, electrode rods, and three electrode level switches, which are widely used in water purification plants, water storage tanks, food factories, pharmaceutical plants, chemical plants, and steel mills.
Electrode type level switches must be properly selected according to the liquid to be used, taking corrosion resistance and heat resistance into consideration. Other factors to be considered in the selection process include the size of the hole for mounting the level switch inside the tank, the size of the electrode rod, and ease of installation and maintenance.
In addition, electrode type level switches cannot be used with insulating liquids due to their measurement principle. If the object is insulating, use a float switch or ultrasonic level switch to control the liquid level.
Principle of Electrode Holder
An electrode holder is one of the components of an electrode type level switch, which is used in combination with a floatless switch and an electrode rod. The electrode holder retains the electrode in the tank and transmits the weak voltage applied from the floatless switch to the electrode rod.
Electrode level switches are used to control the tank liquid level by operating or stopping the pump, or as an alarm for the tank liquid level. The electrode holder itself consists of an electrode rod mounting part, a wiring connection terminal, parts for fixing to the tank, and a cover.
The electrode rod mounting part is generally female threaded and the electrode rod is male threaded, and the connection is made by aligning the threaded holes. The wiring connection terminal serves to hang the weak voltage from the floatless switch to the electrode rod while fixing the wiring terminal. Fixing parts with the tank are generally made of resin to insulate the metal tank and the electrode.