Misunderstandings in the use of the hot wire tester: These incorrect operations may affect the detection results

The hot wire tester, as a key equipment for detecting the flame retardancy of materials, is widely used in industries such as electrical and home appliances. However, improper operation can easily lead to deviation in the test results, which cannot truly reflect the fire safety performance of the material. The following usage misconceptions require users to be highly vigilant.

Misconception 1: Neglecting sample pretreatment standards. Some operators did not preprocess the samples according to standard requirements, such as not adjusting the samples in the specified temperature and humidity environment, or not ensuring that the sample surface is clean and flat. For example, when wet samples undergo hot wire testing, water evaporation can interfere with the flame combustion state, resulting in errors between ignition time and combustion duration; Samples with rough surfaces and uneven contact area of the heating wire can also affect the repeatability of the test. Therefore, it is necessary to strictly follow the standards (such as IEC 60695) to place the sample in a specific environment for at least 24 hours and ensure that the surface is free of oil stains and impurities.

Misconception 2: Setting test parameters incorrectly.hot wire testerThe testing temperature, application time, and other parameters must be strictly set according to the material application scenario. Any arbitrary adjustment will seriously affect the results. For example, when testing the material of household socket shells, if the temperature of the hot wire is reduced from the standard 750 ℃, even if the actual flame retardancy of the material is insufficient, it may still pass the test; On the contrary, if the temperature is too high, it may cause qualified materials to be misjudged as unqualified. In addition, if the application time of the heating wire is not precisely controlled within 30 ± 1 second, it can also lead to distortion of the detection results.

Misconception 3: Ignoring the interference of the experimental environment. The wind speed and air circulation in the testing environment have a significant impact on flame spread. Conducting tests directly in a well ventilated laboratory, air flow may accelerate flame extinction or change the direction of combustion, making the test results unable to truly reflect the flame retardant properties of the material. The correct approach is to conduct the test in a closed, windless environment chamber or use a windproof tester to ensure a stable testing environment.

Misconception 4: Failure to standardize the ignition process. If the contact angle and pressure between the hot wire and the sample are not appropriate during operation, it will result in inconsistent contact area and cause testing errors. For example, tilting the hot wire in contact with the sample may cause local temperatures to become too high, leading to premature ignition of the material. In addition, if residual substances on the surface of the heating wire are not cleaned up in a timely manner after the test is completed, it will affect the temperature accuracy of the next test. Therefore, it is necessary to sand the heating wire with sandpaper to a shiny state after each test.

To avoid the above misconceptions and strictly follow the operating procedures is to ensurehot wire testerThe key to scientific and reliable test results. Only by standardizing the use of equipment can accurate basis be provided for evaluating the flame retardant performance of materials and building a solid product safety defense line.