AWS F1.2:2013 pdf free download

AWS F1.2:2013 pdf free download.Laboratory Method for Measuring Fume Generation Rates and Total Fume Emission of Welding and Allied Processes.
4.1 General Description of SLiggested Chamber
The conical test chamber (Figure 1) is fabricated with holes to allow manual access into the chamber. A sighting window with an appropriate removable shaded lens is located in the center of the chamber to provide visibility for setting up and observing tests. Leveling bolts are provided to maintain an air gap of about 1/2 in to 3/4 in (13 mm to 19 mm) between the base of the chamber and the surface on which it rests. A filter assembly for collecting the fumes, consisting of the filter and its supports, a pressure drop gauge, and a constant flow rate pump, is mounted at the top of the chamber. This arrangement makes the filter accessible for quick and easy changes.
4.2 Equipment Specification for the Suggested Chamber shown in Figures 1 and 2
4.2.1 Filter pad, glass fiber with or without binder, diameter 12 in (305 mm). Any binder present should be temperature stable to 350°F (177°C) (ASTM C8(X), Specification for Glass Fiber Blanket Insulation).
4.2.1.1 Fiber diameter should be the following:
nominal — 0.00005 ± 0.00001 in (1.3 ± 0.3 pm
4.2.1.2 The density should be the following:
nominal — 0.6 ± 0.05 lb/ft3 (9.6 ± 0.8 kg/rn3)
4.2.1.3 Filter pads should have a uniform thickness of the following:
nominal —0.5 ± 0.125 in (13±3 mm)
4.2.1.4 Filter pads shall be uniform in appearance and fiber distribution throughout their thickness. Unstable binders, burnt glass streamers, cuts, tears, holes, and voids are not acceptable.
4.2.1.5 Alternative filter media may be used if it can be demonstrated to be equivalent in performance to the glass fiber pad.
4.2.2 The filter shall he of cellulose fiber (sample collection for analysis); approximately 4 tm effective pore size; diameter 12 in (305 mm), or equivalent.
4.2.3 Air Pump. An air pump capable of sampling at a uniform rate of 25 ft3/min to 35 ft3/rnin (709 L/min to
989 L/min). This flow rate is sufficient to clear the test chamber within 30 seconds.
4.2.4 Suggested Test Chamber. The design features are detailed in Figures 1 and 2.
4.2.5 Plate Movement. Some method of plate movement is needed when an automatic process with a fixed torch is used. This is optional for semiautomatic, hand-held torch operations, but is recommended as it ensures more accurate results. If utilized, the movement apparatus should be capable of maintaining a speed commensurate with the process being used.
4.2.6 Pressure Drop Gauge. This gauge is used to measure the pressure drop across the filter and indicates the degree to which the filter is loaded.
4.2.7 Oven. An oven at 200°F to 225 °F(93°C to 107°C) shall he used to hold filter samples prior to weighing.
4.2.8 Balance. For measuring the fume generation rate, a balance with a sensitivity of 0.01 g or better shall be used for weighing the filter pad before and after testing.
4.2.9 Timer. A timer with a range of 0 minutes to 10 minutes in 0.01 minute increments or smaller shall be used for determining the elapsed Lime of the test.
4.2.10 Voltmeter/Ammeter. Recording instrumentation should be used when possible to accurately monitor welding conditions. The meters should be capable of reading with an accuracy of ± 1/2% of full-scale. It is recommended that such voltmeters and ammeters be chosen so that during tests the meter readings be at least 25% of full scale. Arc voltage should be read from a point on the torch side of the welding circuit as close to the arc as possible; make and model of torch or electrode holder, and the precise attachment point of the voltage lead, should he recorded for future reference.AWS F1.2:2013 pdf free download.