What is the Resistance Decade Box?

The resistance decade box is an electromagnetic relay that can adjust the resistor and display the resistance size of the resistor. If it is compared with the slide rheostat, the slide rheostat cannot express the resistance value of the connected power circuit, but it can continuously change the resistor in the connected power circuit. The resistance box can express the size of the resistance in the power circuit, but the resistance transition is not continuous. The role of the resistance box is that the resistance value of the circuit can be arbitrarily changed, thereby changing the current and voltage of the circuit.

The resistance decade box is a box type resistor. It is made up of several fixed-value resistors with different resistance values connected in a certain way. The constant value resistor in the resistance box is generally wound with constantan and manganese copper wire, so that the resistance value does not change basically with temperature. There are two types of resistance boxes used in the laboratory: plug type and switch type (also called barrel type).

The resistance decade box is an important instrument for electrical measurement in the laboratory. The use of a resistance box can increase the accuracy of the reading. When using a resistance box, it is required to pay special attention that the current through the resistor cannot exceed the allowable value.

Characteristics of the resistance decade box

• High tenacity. Under the operation condition with fierce temperature change, it can still maintain high tenacity and it is not easily to get broken.
• ATO resistance decade box has the best thermal design. The cabinet structure has the best cooling airflow path, eliminating local high temperature points and easy burning points.
• Resistance decade box has complete types. According to the size of the current-carrying capacity, there are a variety of resistance element types such as ribbon, corrugated winding, and smooth winding types.
• The resistance element is modular. It can be arbitrarily combined through series and parallel methods to meet the requirements of various parameters such as voltage and resistance, and it is easy to be replaced.

Operation of the resistance box

When using a resistance decade box, please firstly connect the two terminals to the circuit (the two terminals have no positive and negative poles), and adjust the dial to get any resistance value between 0 ~ 9999.9Ω. (Usually turn the dial in clockwise) The number of indication points corresponding to each dial is multiplied by the multiple marked on the faceplate, and then added together, then the resistance value of the access circuit can be obtained.