The UNILAB Digital Light Fastness Tester is used for determining the colour Fastness of textiles to Light using an artificial Light Source. (MBTL)

1. PRINCIPLE   -A test specimen of the textile together with blue wool standards is exposed under prescribed conditions to the light from a MBTL 500 W Lamp.  The Colour fastness of the specimen is assessed by comparing its performance with that of blue light fastness standards.

2. EQUIPMENT-The unit consists off a hollow cylinder of metal open at both ends with an internal dia of –18� & length of 18� A 500W MBTL fading Lamp is mounted centrally so that the light distribution is constant around the circumference. An hour meter with buzzer and an hour totaliser are mounted on the base.  Four specimen holders are installed at equidistance in inner circumference of cylinder along with metal sheet mask to cover half of each test specimen & the standards. As temperature may touch upto 80^oC constant cooling arrangement with water flow is provided.  A horizontal pump and water tank are included in scope of supply.

3. OPERATION             Firstly the sample (60 x 15 mm) & Blue Wool standards are installed in the sample holders.  In test tubes a small quality of saturated solution of Potassium Carbonate is added to control the humidity.  The sample is then hung from a wire hook in the test tube which is sealed by cork. The sample holders are water cooled & linked in series by plastic tubing.  Water cooling is necessary as the temperature inside the drum can go up to 40⁰ C above ambient temperature & at such levels dye migration may start & affect the light Fastness readings.

Please take care to replace the water in tank once it reaches a temperature of 40⁰ - 45⁰ C.  After samples are at place set the Hour Meter at the no of Hours for which the test is to be performed.  Start the main switch as the Lamp glows.  Start the PUMP switch for water circulation.

4. PANEL                                   MBTL LIGHT FASTNESS TESTER

Power: -   230 V,  50 HZ, Single Phase.