Product Details

1、 Product introduction

The DC resistance test of transformer winding is an indispensable test item after the transformer is handed over, overhauled and the tap changer is changed. By measuring the DC resistance of the transformer winding, you can check the welding or connection quality of the lead, whether the winding has inter turn short circuit or open circuit, and whether the tap changer is in good contact. In the past, QJ44 double arm bridge was used to measure the DC resistance. However, the measuring current of this type of bridge is milliampere level, which takes a long time to measure and has low accuracy. In order to change this situation, shorten the measurement time and reduce the workload of testers, our company has developed this product.

This product is a high-precision replacement for DC single and double arm bridges. The instrument adopts advanced switching power supply technology, whose measurement speed is more than 100 times faster than that of the bridge. The display part displays the measurement results by a four and a half LCD, and the three and a half LCD displays the ambient temperature or test current value, overcoming the disadvantage of other similar products that it is inconvenient to read the values displayed by LEDs in the sun. At the same time, it has the function of automatic arc suppression. The instrument has the advantages of fast speed measurement, high accuracy, intuitive display, strong anti-interference ability, small size, low power consumption, stable and reliable test data, and free from human factors. The instrument is equipped with rechargeable battery pack (14.8V) for both AC and DC, which is convenient for field and field tests.

This product meets the requirements of DL/T 845.3-2004 General Technical Conditions for Resistance Measuring Devices Part 3: DC Resistance Tester.

2、 Purpose

It is an ideal instrument for measuring the DC resistance of power transformer, large motor, mutual inductor and other inductive loads, the contact resistance of low-voltage switch, the resistance of wire and cable or weld interface.

3、 Performance characteristics

1. Fast test speed: The maximum output charging current of the instrument can reach 3A, which can effectively compensate the current inertia of large inductance equipment during measurement, accelerate the core saturation, thus shortening the charging time and improving the test speed, hundreds of times faster than the single and double arm bridges of traditional instruments.

2. High accuracy: In addition to the advanced four terminal measurement method, the instrument also uses advanced constant current power supply technology to keep the charging current of inductive load at a relatively stable value, with stable anti inductance and strong anti-interference ability, thus ensuring the measurement accuracy. And the imported high-quality components are used, with high accuracy and repeatability of the measurement results.

3. Wide measuring range: resistance measuring range is 1 μ Ω~20k Ω, wide range.

4. AC and DC dual-use: The instrument is equipped with rechargeable battery pack, AC and DC power supply, portable design, easy to use and carry.

4、 Technical indicators

1. Service conditions:

Ambient temperature: 0 ℃~40 ℃;

Relative temperature: ≤ 85% RH.

2. Measuring range:

The machine has seven ranges, which are:

one μ Ω～20mΩ;

20 mΩ～200mΩ;

0.2Ω～2Ω;

2Ω～20Ω;