1、EUROPE, CEN *EN*34B 92 W 3404589 OObOLL9 525 N STANDARD NORME EUROPENNE EUROPISCHE NORM EN 348:1992 September 1992 UK 614.895.5:614.873.6:620.1 Descriptors: Personal protective equipment, protective dothing, thermal protection, drip proof protection, weld metal, testing conditions English version Pr
2、otective clothing - Test method: Determination of behaviour of materials on impact of small splashes of molten metal Vtements de protection - Mass of drop, expressed in grams: Linear density of the steel rods, expressed In grams per centimeter: Number of 0,5 g drops, produced at the frequency of 20
3、per minute, re- quired to raise the temperature of the sensor behlnd the specimen by 40 K, the sensor temperature being within i 2 K of ambient tempe- rature at the beginning of the test. Princip1 e Projections of molten metal drops at a polnt on a vertlcal oriented test specl- men and measurement o
4、f the number of the drops required to cause a 40 K tempe- rature rise in a sensor behind the specimen. 5 Apparatus 5.1 Device for producing molten metal drops (see figure 1) The end of a steel rod (clause 5.5) Is melted In the flame of an oxyacetylene welding-torch with orifice dlameter (1,2 i 0.1)
5、n. lhe rod is advanced at a constant speed, for example by means of a variable speed motor wlth a system of pulleys and a cord which is attached to the rod holder at one end and a counter- weight at the other end The axis of the burner jet is perpendicular to the rod. The distance d between the rod
6、and burner tip Is adjustable (see figure 2). The feed rates of oxygen and acetylene are controlled by flowmeters. 5.2 Drop gulde (see f The device is designed cally oriented test Sp gure 3) to collect the drops and to guide them towards the verti- cimen. It comprises a funnel machined from the polyt
7、etrafluorethylene resin and is pro- vided with a support that is adjustable In all three planes. The funnel is In- clined at 45 O to the horizontal plane, its cylindrical part shall allow the passage of a rod with a diameter of (5 i 0,Z) mn. Provide a cover on top of the drop guide and cover the dro
8、p guide when not use. n A CEN *EN*i348 72 3404589 0060323 T5b = Page 5 EN 348:1992 5.3 Sensor for measuring the temperature linked to a recording device lhe sensor support block is machined from a refractory insulating material ha- ving a thermal conductivity of (0,125 f 0,015) W/(m - K) at a 40 OC
9、and a spec fic heat capacity of (1,15 f 0,l) J/(g K), to the dimensions shown in figure 4. Two holes near the centre serve to accept the lead wires to the sensor, and four holes at the corners are provided to attach the block support to the specimen-holding frame. As the sensor, use a platinum resis
10、tor conforming to NF C 42-330 (100 R at O OC, flat, dimensions 12,s mn x 10 mn, polytetrafluorethylene coated).A) On the outer surface of the sensor support block, provide a recess of 13,s mn x 11 mn just deep enough to imbed the sensor so that its surface protrudes (0,s i 0,2) mn. Attach the sensor
11、 in the recess by means of a heat-resistant adhesive. Connect the sensor to an appropriate electronic device which converts the resi- stance change to temperature difference. It shall be capable of discriminating i 0,5 K. 5.4 Holdlng frame for the test specimen The specimen-holding frame also suppor
12、ts the sensor (clause 5.3). It allows the specimen to be maintained under tension by a system of pully-clamps and by a counterweight (see figure 5). Use counterweights of (175 f 5) g on both sides of the test specimen or, alter- natively, fix one end of the test specimen in a clamp and attach a (175
13、 f 5) g counterweight to the other. The position of specimen-holder is adjustable hori- zontally and vertica ly. 5.5 Steel rods The composition of the steel rod Is importanct as it affects the reproducibility of the measurements. The steel shall conform to IS0 636 Type G 1. The linear density of the
14、 rod shall be (0,5 f 0,2) g/cm. 6 Specimen Cut test specimens measuring 120 mn x 20 mn from the laboratory sample at a di- stance of at least 50 mn from the edges of the sample. Fold over the edges of the test specimen at a distance of 15 mn from both ends and staple them so as to enable the specime
15、n to be fastened to the clamps (see figure 6). Cut at least 10 test specimens. Condition the test specimens at least for 24 h in accordance with IS0 139:1973, option 2.2.1 (65 f 2) X RH at (20 f 2) OC, and test within 3 min of removal. 3 type 2006 available at Technique Electronique Gnrale, 155, rue
16、 Dr. Bauer, F - 93400 St. Ouen. This is an example of a suitable product available com- mercially. This information is given for the convenience of users of this standard and does not constitute an endorsement by CEN of this product. CEN *EN*348 92 3404589 O060324 992 M Page 6 EN 348:1992 7 Procedur
17、e Warning: Health and safety of operators On exposure to molten metal, organic materials may pyrolyse with formation of toxic or noxious products. Therefore test according to thls method shall be car- ried out in an enclosure where adequate alr extraction Is available upon the completion of each tes
18、t. Protective gloves shall be worn when handllng hot objects. If close-up Inspec- tion of apparatus or test specimen is required during testing, eye and face pro- tection should be provided. Catch metal drops in a suitable receptacle underneath the specimen holder. 7.1 Test conditions Perform the te
19、st in a draught-free room without any source of heat other th required for the test. The temperature of the test room should not vary by more than f 5 K during tests on each sample. Before performlng the test, bring the temperature of the sensor (insulating Support and probe) to i 2 K of the am- bie
20、nt temperature. 7.2 Preparation and adjustment of steel rod Check the linear density of the steel rods and discard any rod wlth an Incorrect value according to clause 5.5. Set the motor speed so that the steel rod (clause 5.5) 1s fed at the rate of (10 i 1) g/im. Adjust the welding rod and gas flow
21、to produce drops of mass m at frequency f. Determine the mass of a drop m by weighing the rod before and after melting 20 drops and dividlng the mass difference by 20. Determine the frequency by recording with a stop-watch the time necessary to produce a given number of drops, the flrst drop being e
22、xcluded from the count. For the determination (clause 7.3) the mass of a drop m and the frequency f shall be as follows: m = (0,5 f 0,03) g f = 20 drops per (60 f3) sec. For guidance, the following may be used as a starting point: acetylene pressure = 50 kPa2 oxygen pressure d, dlstance from rod to
23、burner jet = 12 mn length of dark-blue cone of flame = 8 mn Aim at the lowest practical gas flow rate so as to minimize the risk that metal drops are blown away or spattered In the flame. Position the roi so that it is at the hottest point of the flame, i. e. just beyond the tip of the dark-blue con
24、e. 3 1 kPa = 10 N/m2 CEN *EN*348 92 3404589 0060325 829 Page 7 EN 348:1992 7.3 Determination Position the specimen holder (clause 5.4) so that the vertical distance between the centre of the burner jet and the horizontal centre-line of the sensor (clause 5.3) is (110 f 10) mn. Adjust the distance be
25、tween the axis of the rod and the vertical Plane of the faCe of the sensor to (60 f 10) mn. Adjust the di- stance between the axis of the rod and the plane through the vertical centre- line of the sensor perpendicular to its faCe to (15 f 10) mn on the side opposi- te to the burner jet (see figure 1
26、). Incline the drop guide (clause 5.2) at an angle of 45 O, ensure that the metal arops are easily collected and that they impnge on the test specimen at the le- vel of the sensor. Set the distance between the external face of the test speci- men and the tip of of guide at (1.5 f 1) mn (see figure 1
27、). Attach the test specimen to the specimen holder by the means of the clamps so that the sensor is entirely covered. Attach the counteweight(s). If the test specimen has an external face, this face shall be exposed to the drops. For each test, note the number of drops x, required to raise the tempe
28、rature of the sensor by 40 K. Test a total of 10 test specimens. To obviate clogging of the drop guide with the first drop (which may be oversi- zed if the rod has cooled from the previous test with a drop about to fall) it is advisable to use a paddle or shutter to deflect the initial drop away fro
29、m the chute. Comnence the test with the next drop. 8 Precision Based on interlaboratory trials of this test the sample standard deviation to be expected is 1,O f 0,6 and the standard deviation of the mean is 0,3 f 0,2. Any individual measurement which deviates by more than 3 drops from the mean valu
30、e should be considered an outlier and discarded. Any test giving a standard devia- tion greater than 1,6 should be checked and possibly repeated. 9 Test report The test report shall include the following partlculars: a) reference and description of the sample from which the test specimens were taken
31、, in particular its surface density, in grams per square metre; b) a reference to this European Standard; c) the results obtained on each of the test specimens and the mean value of the results; d) observations of any noteworthy phenomena (smoke, flames, etc.) e) procedural details not specified in
32、this European Standard as well as any in- cident noticed which may have affected the test results or which may repre- sent an aggravation of possible hazards. CEN *EN*34 92 m 3404589 00b012b 765 m Page 8 EN 348:1992 P *4 o! -1 I- 60 :i0 l Illm It I Sewr I figure 1 - Gonorai arrangement of apparatus
33、for producing molten metal drops CEN *EN*348 92 3404587 0060327 bTL W Page 9 EN 348:1992 ,- Moior WMmg rorcn I frame k figure 2 - Device for producing molten metal drop. CEN *EN*348 92 3404589 0060328 538 m Page 10 EN 348:1992 Dimensions in rniiiime t- 50 A-A NOTE - li is rommenoea to fabncmc the fu
34、nnef ana guide rube mom seoammv and to oresfit them togcmcr Figure 3 - Drop guide r o1 -i CEN *EN*348 92 m 3404589 0060329 474 m - 50 t I 10 I I l - 1 O m Page 11 EN 348:1992 Dimerruons in millimeves Figure 4 - Sensor ruppon block Figure 5 - Specimen SUPOK CEN *EN*:348 92 3404589 0060130 176 m f Pag
35、e 12 EN 348:1992 Dimerrsons in millimaam figuro 6 - Tm spocimon CEN *EN*348 92 3404589 00bOL31 O22 EUROPEAN STANDARD NOWE EUROPEENNE EUROPISCEE NORM EN 348 AC: 1993 January 1993 Janvier 1993 Januar 1993 English version Version franaise Deutsche Fassung Amends EN 348, September 1992 Amende EN 348, Se
36、ptembre 1992 ndetunq EN 348, September 1992 Protective clothing - Test method: Determination of behaviour of materials on impact of small splashes of molten metal Vtements de protection - Mthodes dessai: Dtermination du comporte- Verhaltensbestinunung von Materalien ment des matriaux au contact avec
37、 bei Einwirkung von kleinen Spritzern des petites projections de mtal liquide Schutzkleidung - Prfmethode: geschmolzenen Metalls This corrigendum becomes effective on 1993-01-29 for incorporation in the English version of the EN. Ce corrigendum prendra effet le 199341-29 anglaise de la EN. pour intr
38、oduction dans la version Die Berichtigung tritt dm der EN einzufgen. 199341-29 in Kraft und ist in die englische Fassung CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Rue de Staseart 36, B - 1050 Brussels c CEN 1993 Copyright reserved to ali
39、 CEN members Droits de reproduction rservs aux membres du CEN Das copyright ist allen CEN-Mitgliedern vorbehalten Ref. no. EN 348:1992/AC:1993 E/F/D CEN *EN*348 92 m 3404589 0060332 Tb9 m Page 2 Page 2 Seite 2 ES 348: i992:AC: 1993 E : On page 4 of the English version. clause 5.1. paragraph 1. replace the last word “hand“ by the word “end“. F : Sur la page 4 de la version anglaise, article 5. i. alina i. remplacez le dernier mot “hand“ par le mot “end“. D : Auf Seite 4 der englischen Fassung, Abschnitt 5.1, Absau 1, ersetze das leme Wort “hand“ durch das Won “end“.
