DC Potentiometer

Brand: CL

Model: UJ33A

Pictures are for reference only.

A DC potentiometer is an instrument for measuring potential difference with high precision, based on the principle of mutual compensation (i.e., balance) between the measured voltage and the known voltage. Its main advantage over a voltmeter is that it does not require the circuit to be measured to supply current, thus not affecting the circuit to be measured, and can accurately measure the electromotive force of the power supply. There are generally two types: the rotary handle type and the sliding wire type. Due to the use of the potential compensation method, the measurement accuracy is high. The error caused by the internal resistance of the power supply is avoided, and the terminal voltage is measured when no current flows through the power supply, which greatly improves the accuracy and sensitivity [1]. The characteristic of the compensation method is that it does not draw current from the measured object, thus not interfering with the measured value, and the measurement result is accurate and reliable. The potentiometer has a wide range of uses. When equipped with standard batteries, standard resistors and other instruments, it can not only measure electrical quantities such as electromotive force, potential difference (voltage), current, and resistance in situations where high accuracy is required, but also can be used to measure and control non-electrical quantities such as temperature and displacement when equipped with various transducers.
Principle
When no current flows, the potential difference between the positive and negative electrodes of the battery is equal to the electromotive force of the battery. If current flows, there will be a certain voltage drop on the internal resistance of the battery (this is the case when using a voltmeter to measure the voltage between the two poles of the battery). At this time, what is measured is no longer the battery electromotive force, but only the terminal voltage. If the measurement can be performed when there is no current flowing, the electromotive force can be measured directly. The compensation method is such a method.
Potentiometers are divided into two types: AC and DC, and are widely used in production and scientific research. For example, when producing semiconductor materials and components, thermocouples composed of platinum-platinum-rhodium alloy are often used to measure furnace temperature. The change in thermoelectric electromotive force is only tens of microvolts, which is not suitable for measurement with a voltmeter. Generally, a potentiometer is used. Potentiometers are also used to accurately measure current and resistance. AC potentiometers can be used for magnetic measurement.