Self-limiting temperature electric heating cable detection is a systematic and comprehensive process, and its detection methods usually cover multiple aspects to ensure the quality and performance of the product. The following are some of the main detection methods:

1. Appearance inspection
Flatness and smoothness: Use visual inspection to check whether the appearance of the self-limiting temperature electric heating cable is flat and smooth.
Defect inspection: Observe whether there are defects such as cracks, bubbles, scratches, breakage, deformation, etc.
2. Dimension measurement
Tool selection: Use a vernier caliper or micrometer for measurement.
Measurement content: Measure the width, thickness, length, and other dimensions of the self-limiting temperature electric heating cable to ensure that it meets the requirements of the product standard.
3. Resistance measurement
Tool selection: Use a multimeter or resistance tester.
Measurement method: Contact the test probes at both ends of the electric heating cable respectively, read the resistance value, and check whether it meets the standard requirements.
4. Insulation resistance measurement
Tool selection: Use an insulation resistance tester.
Measurement method:
For electric heating cables with metal shielding layers, apply a voltage between the two wires connected together and the metal braided layer to measure the insulation resistance value.
For electric heating cables without metal shielding, immerse them in water (with the conductors at both ends exposed to the water surface), apply a voltage between the two connected wires and the water, and measure the insulation resistance value.
When using DC and 1KV megohmmeters for measurement, ensure that the megohmmeter is evenly shaken for 1 minute before reading, and the insulation resistance is not less than the specified value (such as 20MΩ).
V. Temperature measurement
Measurement of maximum maintained temperature:
Put the self-limiting temperature electric heating cable in a constant temperature box and gradually increase the temperature.
Record the temperature change until the temperature no longer increases, and the temperature at this time is the maximum maintained temperature.
Measurement of minimum maintained temperature:
Put the self-limiting temperature electric heating cable in a low-temperature box and gradually reduce the temperature.
Record the temperature change until the temperature no longer decreases, and the temperature at this time is the minimum maintained temperature.
Surface temperature measurement:
Install the electric heating cable on a simulated pipeline and pass the rated current.
An infrared thermometer is used to measure its maximum surface temperature and check whether it meets the standard requirements.
VI. Measurement of maximum use length
Method: Connect the self-limiting temperature electric heating cable to the power supply and gradually increase the length.
Determination: Record the temperature change until the temperature stops rising. The length at this time is the maximum use length.
VII. Power density measurement
Tool selection: Use a power meter.
Method of measurement: Measure the power density of the self-limiting temperature heating cable to check whether it meets the requirements of the product standard.
VIII. Thermal stability measurement
Method: Put the self-limiting temperature heating cable into a constant temperature box and run it continuously for a certain period of time (such as several hours or days) at the highest maintenance temperature.
Determination: Record the temperature change to check whether it is stable and reliable and whether it meets the requirements of the product standard.
IX. Corrosion resistance test
Method: Soak the self-limiting temperature heating cable in corrosive media such as acid, alkali, and salt for a certain period of time (such as several hours or days).
Determination: After taking it out, rinse it with clean water, and then use visual inspection to check whether there is corrosion in its appearance.
X. Other precautions
Safety: When conducting inspections, ensure the safety of all equipment and tools and comply with relevant safety operating procedures.
Accuracy: During the measurement and testing process, ensure the accuracy and reliability of the results to avoid errors and deviations.
Comprehensiveness: The test should cover all relevant performance and parameters to ensure the overall quality and performance of the product.
In summary, the test methods of self-limiting temperature heating cables include appearance inspection, dimension measurement, resistance measurement, insulation resistance measurement, temperature measurement, maximum use length measurement, power density measurement, thermal stability measurement, and corrosion resistance test. Comprehensive testing can ensure that the quality and performance of self-limiting temperature heating cables meet relevant standards and requirements.