The detection distance of the digital insulation resistance tester refers to the distance at which the tester can detect the cable under test. This distance is affected by many factors, including the tester’s sensitivity, the length of the cable under test, and the way the cable is laid. Generally speaking, the detection distance of an insulation resistance tester ranges from tens to hundreds of meters, depending on the model and performance of the tester.
Main Factors Affecting Detection Results:
Length of the Measured Object:
- For long-distance cables or large equipment, the digital insulation resistance tester may be affected by the cable’s length or the device’s size. Longer cables or larger equipment may result in higher leakage currents, affecting the measurement results. For power equipment or long-distance cables, it is crucial to maintain proper distance between conductors to avoid leakage currents influencing measurement accuracy.
Test Voltage:
- The test voltage range (typically from 250V to 2500V) directly impacts the measurement outcome. High-voltage equipment requires higher test voltages (such as 2500V or 5000V) to improve the detection of insulation performance. Appropriate test voltage enhances measurement accuracy and ensures more effective measurements of high-voltage equipment.
Environmental Conditions:
- Environmental factors like temperature and humidity can affect insulation performance. Higher humidity can cause insulation materials to absorb moisture, which reduces insulation resistance. Therefore, special attention should be given to environmental factors when performing long-distance tests in humid environments, as they can potentially influence the results.
Methods to Improve Long-Distance Detection Accuracy:
Using Shielded Cables:
- When testing long-distance cables, using shielded cables helps reduce external interference and leakage currents, thereby minimizing their effect on the measurement results.
Increasing Sampling Frequency:
- Modern digital insulation resistance testers come equipped with automatic sampling frequency adjustment features, which can help improve measurement accuracy during long-distance tests, especially in complex environments.
Regular Calibration of Instruments:
- Regular calibration of the insulation resistance tester is essential to ensure the instrument maintains good measurement accuracy over time. Calibration becomes especially important when the instrument is frequently used or in harsh testing conditions.