Glow Wire Test Apparatus – Glow Wire Test Method, Definition & Operating Steps

Glow wire test apparatus is suitable for the research, production and quality inspection department of lighting equipment low-voltage electrical appliances, electrical instruments and other electrical and electronic products and their components. Glow wire test apparatus is a simulation test item of IEC 60695-2-10, UL746A and other standards that use non-flame ignition source program. The glow wire test apparatus rule the specified material (Ni80/Cr20) and shape of the heating wire (Φ4 mm resistance heating ulloys) to the test temperature with a large current.

Test temperature : 550 ℃ ～ 960 ℃, 1 minute later, Burn test sample vertically for 30 seconds at specified pressure (1.0N), To determine the fire risk of finished electrical and electronic equipment by observing whether the test sample and matting start or stay burning. To determine the ignition temperature (GWIT) , flammability and flammability index (GWFI) of solid insulation materials and other solid combustible materials, Also suitable for insulation materials engineering plastics or other solid combustible materials industry.

Glow-wire test apparatus parts of insulation or other solid combustible materials that are prone to flame spread within the equipment may be ignited by glow-wire or searing elements. Under certain conditions, such as overload of the fault current elements flowing through the wires and poor contact, Some components reach a temperature that causes nearby components to ignite. Glow-wire testing machines are used to evaluate heat sources due to scorching elements or overload resistances using simulation techniques, Ignition risk of thermal stress in a short period of time.

The suction relay is used to control the depth of the searing wire into the sample, and it has the function of adjustment, and is equipped with measuring gauge, which is accurate and fast. The thermocouple imported from Britain is used for accurate temperature control. Omron relay, timer, Merlin Rilan leakage protector, red wave button and other well-known brands are used to ensure the operation. When the searing wire contacts the object under test, the glow wire test machine will continue to supply power, and the current will be cut off within 2 seconds after the sample car returns, so as to ensure the accuracy of the test. Glow wire test apparatus from Wewon Environmental Chambers equipped with mesh transfer sample fixture, easy to clamp abnormal & small sample. Lighting lamps and lanterns using standard explosion-proof lamps, in line with safety standards. The case is made of 1.2 mm stainless steel. The main field sealed exhaust fan is used to ensure the sealing of the box. And the exhaust effect is strong. The glow wire test equipment is simple to operate, the temperature measuring system is stable and reliable, and the automatic temperature compensation. Timer and temperature control meter adopt imported instrument (Otonix), accurate measurement.

Performance Feature

●	How to Operate the Glow Wire Test Apparatus ? What is the Glow Wire Test Apparatus Price ?
●	Fix the test item on the test rack and adjust the required size of test insertion. Plug in the power supply at the back of the chassis and confirm whether the incoming power supply is well grounded. The power supply voltage is AC220V.
●	Adjust the chronograph, Turn on the power switch and check whether the instrument is normal.
●	Press the start button to enter the test when the value shown in the thermometer reaches the required temperature. When the heating time is finished, the sample carrier will detach automatically, Stop heating.
●	Observe the residue dropped in the burning process of test article, burning and test article to extinguish immediately according to the phase key, when burning record the flame height. At the end of the test, press the exhaust button to exhaust the smoke.
●	Power switch off the glow wire test apparatus.｜Remove the test product, record the test results, clean the dirt in the box, close the exhaust outlet, and close the main power switch.

●	Be sure to read the instructions carefully before using and follow the instructions. Do not use accessories not provided by the original factory to avoid risk.	Operation Procedure
●	The glow wire test apparatus is placed in a room with degreasing ventilation equipment (or in a small laboratory with a special ventilation hood) for exhaust gas discharge after the test.
●	Two matching weights are suspended below the bracket plate through two pulleys at the left end of the bracket (through corresponding holes) with copper wires (connected to the sample bracket).
●	Mount the sample according to test standard requirements｜Proximity switch adjustment｜Loosen the nut holding the proximity switch so that it moves left and right.
●	Press the “Left Button” to move the car automatically. When the sample touches the hot wire, move the proximity switch by hand to stop the car and fix the proximity switch.
●	Press the “Heating” button to adjust the current regulating knob. According to the sample requirements, adjust the appropriate current value and see if the temperature meets the test requirements.
●	When the test sample touches the hot wire head of glow wire test apparatus, the limit electromagnet is released, and the pulling force of 1 N weight can only move forward 7 mm.
●	At the end of the experiment, the heating button will pop up and the current adjustment knob will be rotated to the minimum.

Glow-wire test apparatus is based on test standard IEC60695-2-10: 2000, GB/T5169.10-2006, GB/T5169.13-2006 and GB4706.1 “glow-wire test method” to design and manufacture. Glow wire tester is suitable for fire hazard test of electrical and electronic products and household appliances and their materials. To simulate the thermal stress caused by a heat source or ignition source such as a searing element or overload resistance for a short time.

Glow wire testing apparatus is designed with test box part and control part, which is convenient for field installation and debugging. The shell and important parts of the environmental test chamber are made of stainless steel. The automatic control system of smoke resistant silicon adjusts the current automatically, To achieve the purpose of accurate temperature control. Digital display of time and temperature, convenient observation and recording, stable and reliable use.

	IEC 60695 2-10 International Standard Fire hazard testing – Part 2-10 Glowing/ hot-wire based test methods – Glow-wire apparatus and common test procedure
	IEC 60695 2-13 British Standard Fire hazard testing – Part 2-13 Glowing/ hot-wire based test methods – Glow-wire ignitability test method for materials
	IEC 60695 2-12 International Standard Fire hazard testing – Part 2-12 Glowing/ hot-wire based test methods – Glow-wire flammability test method for materials
	UL 746A STANDARD FOR SAFETY Polymeric Materals- Short Term Property Evaluations
	DIN VDE 0620-1 (VDE 0620-1) 2005-04 Plugs and socket -outlets for household and similar purposes-part 1:General requirements

Glow wire test machine is mainly used for electrical and electronic components or parts which may reach too high temperature or ignite the parts near them under the condition of failure or overload, Glow-wire tests simulate the thermal stress caused by a source of heat, such as a searing element or an overloaded resistance, over a short period of time, Fire risk assessment using simulation techniques, It is suitable for plastic and non-metallic insulating material parts used in electrical and electronic products, such as switch housing, relay socket, etc

Glow-wire test apparatus performs fire hazard test and combustion performance test, Simulate under fault or overload conditions, The thermal stress caused by a heat source or ignition source, such as a hot element or overload resistance, over a short period of time to assess the risk of ignition. The control system of IEC60695 glow wire tester apparatus is highly automatic, and imported parts are used for temperature control, High measuring accuracy, digital display of time and temperature, convenient observation and recording, stable and reliable use. The shell and important parts of the test chamber are made of stainless steel, resistant to smoke corrosion.

Before the test, in the process of calibration, if it is found that the temperature cannot rise or the size of the heating parts decreases too much, the searing wire heating parts should be replaced in time. Common process needs to replace thermocouple and heating parts. When replacing the thermocouple, check whether the hole in the head of the heating part is blocked. If it is blocked and cannot be cleaned, replace the heating part.	1. Replacement of Glow Wire Parts	Replacement of Glow Wire Parts and Glow Wire Test Apparatus Calibration Process
For new heating parts, sandpaper should be used to polish them before installation, Remove burr and coating from the surface to facilitate heating when the heating part is energized. Special care should be taken to clean the holes in the head of the heating part. If the holes are blocked, they cannot be used. After polishing the heating part, fix it between two bolts. The distance between the head of the heating part and two bolts should not be too short. It should be as appropriate as possible, as the exposure is too short to cause the resistance to decrease, the current through the heat is not enough to rise to the required temperature.
After fixing the heating parts, install the thermocouple and connect the thermocouple. Pass through the gap in the middle of the heating part, and insert the head of the thermocouple into the hole in the head of the heating part. In order to make the heating effect good, should make the thermocouple head insert angle slightly with the horizontal plane into a certain angle. Make thermocouple has a forward force against the hole, in order to achieve fixed purpose, make the heating more full.
After installing the heating part head, the temperature measuring system of the heating part should be verified, A silver foil with purity of at least 99.8%, area of about 2 mm2 and thickness of about 0.06 mm is placed on the top surface of the heating part to complete the single point verification of temperature. After the silver foil is placed, the glow wire test apparatus is heated at an appropriate heating rate. When the silver foil begins to melt, the thermometer for the heating part shall display 960℃±15℃. The heating parts should be cleaned immediately after the confirmation procedure is completed. All silver residues are removed at high temperatures to reduce the likelihood of melting into alloys.	2. Temperature Calibration of Heating Components
A good way to test the fire hazard of electrical and electronic products is to present the actual conditions. But in most cases it’s not possible. Therefore, according to the real situation to simulate the actual effect as much as possible to carry out electrical and electronic fire hazard experiment.
Components of electrical and electronic equipment may be exposed to overheating stress due to electrical action, and their deterioration may reduce the safety performance of the equipment. These parts should not be unduly affected by the heat and fire generated within the equipment. Parts of insulation or other solid combustible materials that are prone to flame spread within the equipment may be ignited by hot wires or elements.

This glow wire test apparatus must use voltage regulator power supply, otherwise the temperature will be affected by excessive voltage fluctuation. Searing wire should not work for a long time under high temperature, so as not to shorten the service life of thermocouple. After each use, the current should be reduced or disconnected from the power supply. After each test, clean the combustion chamber in case of power failure, and take care not to collide the thermocouple and hot wire. After the test is completed, the user can use the exhaust fan to discharge the exhaust gas generated during combustion, but do not turn on the fan during the test, so as not to affect the test results. If maintenance is needed, especially replacement of searing wire, attention should be paid to re-tighten the screws that have been driven, otherwise users who have bad contact with the current circuit and high temperature interface should tighten all screws after replacing parts. This glow wire test machine has the overtemperature protection function, when it reaches the set temperature, it will automatically disconnect the heating circuit, therefore, the preset temperature cannot be lower than the normal operating temperature, otherwise it cannot work normally.

Notification Agreement

Before conducting the heating part test, the glow wire test apparatus shall keep the heating part on a horizontal surface. In addition, the heating component should exert a force of 1.0 +0.2N on the test sample when it is used. The penetration depth of the top of the heating component into or through the test sample should be limited to 7 mm (+0.5 mm).	1. Glow Wire Test Apparatus not Calibrated Before Test	Reasons for Replacement of Glow wire｜Why You Need to Replace the Glow Wire for Testing Apparatus ?
Because the size and shape of the test sample are difficult to fix, sometimes the size or shape of the sample may lead to contact with the top of the heating part, The sample penetrates too deeply, causing residue to enter the head of the heating part and block the hole.
Therefore, before the test sample is fixed, the distance between the fixture trolley and the head of the heating part should be carefully checked. Ensure that the vehicle does not melt and block the holes in the heating parts due to too small a distance during the test.
In normal use, different test temperatures are set according to different samples due to the searing wire test, Often in the lower temperature test because of the low temperature, can not be the heating parts of the residue solid burning, It is usually necessary to clean the heating part head with a steel brush, This can easily lead to residues in the gap of the heating part head, which is not conducive to heating.	2. Cleaning Problem During Glow Wire Test
Meanwhile, When cleaning with a steel brush, the thermocouple is often inadvertently touched, causing the thermocouple to slip out of the hole or loose.
Glow-wire tests are frequent due to the requirements of general electrical and electronic products for fire hazards, The service life of searing wire heating parts is generally about 3~4 months. All the glow wire test equipment should be inspected and maintained before the experiment to extend their service life.	3. Normal Test Loss for Glow Wire Test Apparatus
Glow wire test procedure is an important way to check the fire safety of insulation materials or other solid combustible materials which are easy to spread flame inside the equipment, It is an important basis to determine whether the material can be used in harsh environment.
The UL glow wire test equipment itself is actually a fixed size resistance wire ring, The test should be heated to the specified temperature by electricity, The top contact time of the glawing wire heating component to the sample standard, Observe and measure its state again, the scope of the test depends on specific test procedures. If you are looking for the tracking test apparatus for performance testing of insulating materials, please visit the related flexible cables testing webpage.
The glow wire heating element is made of nickel/chromium (80/20) wire with a nominal diameter of 4 mm. The glow wire are heated by a large current through a simple circuit, Therefore, the glow-wire electrical connection should ensure the long-term stability of the circuit through large currents without affecting the performance of the circuit.
But in practice, the heating parts are in a high temperature state for a long time. Coupled with the pressure action, easily caused damage, need not be replaced regularly. The replacement process is complicated, and calibration is involved after replacement. Therefore, the replacement of heating parts should be paid attention to by users.

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