Standard requirements of the glow wire test device

All electronic products need to consider fire risk and potential fire hazards when designing. The design of components, circuits, products, and materials of materials need to be considered the risk of fire and the risk of potential fire. The purpose is to reduce the potential fire risk caused by the normal operation and foreseeable abnormal use, the potential fire risk caused by failure and failure when the failure and failure are invalidated. Acceptant level. The above-mentioned potential fire risks are provided with IEC60695-1-10 and IEC60695-1-11.

IEC60695-1-10 and IEC60695-1-11

The primary purpose of IEC60695-1-10 and IEC60695-11 is to provide guidance for the following behaviors:
1. Preventing the combustion of the tape parts
2. If the burning occurs, the fire will be limited in the shell of the electrical electronic product

The secondary purpose is to spread the flame to the minimum of the outside of the product, and to minimize the harmful effects of fire sources, smoke, toxicity and corrosive combustion flow. The fire involving electrical and electronic products may also cause fire due to non -electrical external factors. The overall risk assessment should consider this factor.

In electrical equipment, overheating metal components can be used as the source of ignition, and in the hot wire test, the burning sources are simulated with glow wire.

Basic requirements for glow wire test device
The glow wire is made of nickel/chromium (> 77%Ni/20 ± 1%CR) wire with an outer diameter of 4.00mm ± 0.07mm (before bending). The size of the glow wire ring is shown in the figure.

The size of the glow wire ring

Glow wire test producer

Note: The annealing is to prevent small cracks from appearing on the top

A new glow wire tester needs to anneal 10h in the 120A current before the test. In order to avoid damage to the thermocouple, the thermocouple is needed during the annealing. At the end of the annealing, the depth of the thermocouple microphone needs to be confirmed.

glow wire tester

During the test process, the glow wire and the sample should be maintained at a horizontal plane. During the test process, the glow wire should deal with the force of 0.95n (± 0.10N). Within (± 0.5mm). The burning particles on the sample must be able to open the bottom layer of dripping.

2. Test circuit and connection
As shown in Figure 2, this is a simple and simple circuit, which has no feedback device or circuit maintained temperature. The power supply of the glow wire test device should be a stable voltage source (± 2%RMS). The test circuit should contain a current measurement device, indicating that the maximum error of the real valuable value is within 1%.

Test circuit and connection

3. Temperature measurement system
1. The temperature at the top of the burning wire should be measured by the mineral insulation metal armor filaments with a level 1 standard (see IEC60584-2).
2. The diameter of the thermocouple should be 1.0 mm.
3. The thermocouples need to be continuously operated continuously under the conditions of up to 960 ° C (for example: nickel, chromium, nickel and aluminum alloy wire (K type), see IEC 60584-1).
4. The welding point should be located in the armor cover and approach the top as close as possible.
5. The armor cover should be made of metal to ensure that it can work continuously under the condition of at least 1050C.
6. You can use other temperature measurement instruments. If there is controversy, the thermocouple method must be used.

4. The prescribed bottom layer
In order to evaluate the possible combustion and spread, a specified bottom layer is placed below the sample. It requires: a piece of wrapped layer of silk paper on the top of a wooden board (smooth and minimum thickness), placed at 200mm below the burning silk sample, 200mm below the hot silk sample. (± 5mm). Packing silk paper needs to meet the 4.215 regulations of ISO4046-4: 2002. It is a soft and tough lightweight packaging paper with a unit area of 12g/㎡ ~ 30g/㎡.

The prescribed bottom layer

5. Test Chamber
The test box should run in a ventilated environment, and its volume should also meet the following conditions:
• Oxygen loss during the test cannot significantly affect the test results
• The sample needs to be installed at least 100mm from the surface of the test box

6. Device
The timing device should have a resolution of ≤0.2s

Examination of test device
1. The top of the glow wire
Before each series of tests, the temperature of the top of the glow wire is needed to be measured and recorded. If the temperature measurement value on the top of the glow wire is reduced to 97.5%of the readings before the initial test, the glow wire should be replaced.

The top of the glow wire

Each test is completed, and the following inspections are required:

1. Clean the scorching wire on the top of the last time of all trial materials (can be used for cleaning and other tools for cleaning)
2. Check whether there are residues such as cracks and glass fibers on the top of the burning wire. If it is not destroyed, it cannot clean its top, and you need to replace the glow wire.

2. The verification of the temperature measurement system
According to regulations, the following procedures are used for the following procedures for the application of the temperature measurement system (silver foil verification method):
1. Silver foil with a purity of at least 99.8%of the purity is about: 2mm * 2mm * 0.06 (long*width*height) silver foil, placed on the top of the top of the hot wire to complete the single -point verification of the hot wire temperature temperature Essence.
2. The starting temperature of the burning wire should be set to slightly lower than the silver foil melting point and make it stable.
3. Heat the glow wire at a low heating rate in order to accurately observe the melting point.
4. When the silver foil starts to melt, the thermometer should show 960 ° C (± 10 ° C). After the confirmation procedure is completed, all silver foil residues on the hot silk should be removed immediately to reduce the possibility of its melting into alloys.
5. If there is controversy, the silver foil verification method should be adopted.

LISUN ZRS-3H Glow-wire Test Apparatus is according to IEC60695-2-1, IEC60695-2-10, IEC60695-2-11, IEC60695-2-12, IEC60695-2-13 (GB/T5169.10, GBT5169.11, GBT5169.12, GB/T5169.13) < basic testing methods of Glow wire, basic testing methods of Glow wire device>, UL 746A, IEC829, DIN695 and VDE0471.