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Advantages of GLOW WIRE TEST APPARATUS
2017/12/12
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GLOW WIRE TEST APPARATUS is intended for testing the flammability and ignitability of components and materials. It includes electronic feed back heating current stabilizer ‑ regulator, A‑meter, thermometer, motor drive, timer and remote controller.
Current stabilizer insures better repeatability of test results- by maintaining the same current as you set on beginning through the whole test, to avoid the following possibility: during the setting of heating current needed for temperature (e.g. 960 deg. C) the network voltage was 230V. At that voltage current 130 A results in 960 deg. C. Than you begin the test. The voltage in the network drops (or oscillates) to 225V, which is approx 2% and this would result in different current and different temperature (18 deg. C difference).
If you have the current stabilization, even if the voltage drops to 225V, the heating current will be still maintained at 130A and will ensure better results - repeatability improves.Of course if you do not like or do not need current stabilization you can switch it off.
Due to the high currents involved, the wire loop is hard soldered to two stainless steel discs with smooth and large contact surfaces that ensure constant contact resistance (which means constant current during the test). This is important because if it was not hard soldered, contact resistance between loop and stud (column) can change because of oxides formation due to the heat. That would result in change of current and temperature which are the main parameters of this test. Again repeatability of test results improves.
The temperature stability depends very much on air movements around the glow wire loop. Remote controller enables operation of glow wire test apparatus inside closed test chamber. Test chamber enables draught-free conditions, has volume of more than 0,5 m3, and has black painted inner walls as per standard requests. Draught-free conditions again mean more stable temperature and better repeatability of test results.
After the conditions stabilize, you can press START button on remote controller , the complete test is executed automatically, just record the height and duration of the flames and start the ventilator after the test is finished.
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