【正文】 the maximum scale value for 200 000 cycles. 15 000 cycles are sufficient for gauges of classes 0,1。 for indoor use: IP 31。 for outdoor use: IP 44. Effect of mechanical shock After the application of shock loads of 150 m/s2, the gauge shall remain within its accuracy class. The shock test is required for gauges with accuracy classes 1 to 4 only. Effect of mechanical vibration The gauge shall be subjected to vibrations on three orthogonal axes of the following conditions: 177。 177。 177。 l/s. Mounting position A variation of the nominal mounting position of 58 shall not give a change of indication of more than 0,5 times class. Dials and pointers Scale angle The scale normally covers 2708 of arc, but may be longer for accuracy classes 0,1, 0,25 and 0,6. Scale interval The scale interval shall be a value that represents 1 3 10n, 2 3 10n or 5 3 10n of the pressure unit, where n is the whole number which can be positive, negative or zero. The minimum number of minor scale divisions for each class of accuracy and size of gauge are as shown in table 14. For illustrative examples see annex A. Scale marks The thickness of the scale marks shall not exceed 1/5 of the scale spacing. Examples are shown in annex A. Table 14. Minimum number of minor scale divisions Scale Nominal size Minimum number of minor scale divisions Accuracy classes 0,1 0,25 0,6 1 1,6 4 0 to 100 40 50 63 208。 208。 208。 208。 208。 208。 208。 500 208。 200 200 208。 208。 50 208。 208。 208。 208。 208。 208。 208。 32 32 32 32 32 32 32 32 32 32 80 100 150 and 160 250 208。 208。 208。 80 80 80 32 32 32 32 32 32 32 32 32 208。 208。 208。 0 to 250 40 50 63 208。 208。 208。 208。 208。 208。 208。 500 208。 125 250 208。 208。 50 208。 208。 208。 208。 208。 208。 208。 20 20 20 20 20 20 20 20 20 20 80 100 150 and 160 250 208。 208。 208。 80 80 80 40 40 40 40 40 40 40 40 40 208。 208。 208。 0 to 600 40 50 63 208。 208。 208。 208。 208。 208。 208。 300 208。 120 300 208。 208。 60 208。 208。s discretion. Examples of scale numbering are shown in annex A for accuracy classes from 0,6 to 4. Pointer dimensions The tip of the pointer that sweeps the scale mark shall be no wider than the minor scale mark. The pointer shall cover between 1/10 to 9/10 of the length of the shortest lines of the minor scale marks. The minimum lengths of pointer from the axis to the tip are shown in table 15. Table 15. Minimum length of pointer Gauge nominal size mm Minimum length of pointer mm 40 50 63 80 100 150 160 250 14 18 23 28 36 57 62 95 Mirror scales Pressure gauges of accuracy class 0,1 shall be equipped with a mirror scale. Pressure gauges of accuracy classes 0,25 and 0,6 shall incorporate provisions to minimize parallax errors, such as a knife edge pointer. A mirror scale may be fitted in addition. Information on dial a) The unit of pressure shall be marked. b) The accuracy class shall be marked, preferably at the end of the scale. c) The symbol for the type of pressure element may be marked, see table 16. d) Gauges suitable for maximum steady working pressure equal to the maximum scale value shall have an identifying mark at the maximum scale value (see figure 8). e) The symbol for the dial plane shall be marked when the manufacturer is required to calibrate the gauges other than in the vertical position (see figure 9). f) If the customer requires the gauge to be calibrated at other than the reference temperature this shall be marked. This applies to 0,1, 0,25 and 0,6 class gauges. g) If the gauge meets the accuracy requirements on only gas or liquid, then this shall be marked. This applies to 0,1, 0,25 and 0,6 accuracy class gauges. h) The EN number of this standard may be marked. i) The name or logo of the manufacturer and/or supplier shall be marked. j) Serial numbers shall be marked for accuracy classes 0,1 and 0,25, and may be marked for accuracy classes from 0,6 to 4. Serial numbers shall also be marked on all gauges which are subject to state metrological control. k) Where the gauge has wetted parts different from brass, bronze, tin or hard solder, then the material of the wetted parts may be marked. l) Safety pattern gauges shall be marked as specified in . m) Pressure gauges for use with oxygen or acetylene shall be marked as specified in . Pointer stop Gauges with maximum steady working pressure equal to the maximum scale value shall have a free zero. Gauges with maximum steady working pressure 75 % of the maximum scale value may have a free zero. Safety Safety gauges shall protect an operator from failure of the pressureresponsive element and the release of high pressure gases into the case by deflecting the blast and debris away from the front of the gauge. Blowout device gauges When a blowout device is fitted to a pressure gauge, (designated by S1, see clause 12), it shall be resistant to blocking by debris and dirt and shall operate at a pressure of not more than half of the windowburst pressure. Where the gauge is sealed for the purpose of liquidfilling a blowout device shall be fitted. These gauges shall have no special marking. Figure 8 BSI 1998 Page 12 EN 8371 : 1996 Figure 9 Safety pattern gauges This standard defines two types of safety pattern gauges: a) 40 to 80 size safety pattern gauges without a baffle wall (designated by S2, see clause 12)