《ISO-1607-2-1989.pdf》由会员分享，可在线阅读，更多相关《ISO-1607-2-1989.pdf（7页珍藏版）》请在三一文库上搜索。
1、INTERNATIONAL STANDARD IS0 1607-2 Second edition 1989-1 l-01 Positive-displacement vacuum pumps - Measurement of performance characteristics - Part 2: Measurement of ultimate pressure Pompes primaires volum test header: A chamber of specified form and dimensions attached to the inlet of the pump thr
2、ough which a measured flow of gas may be admitted to the pump, and which is equipped with means of pressure measurement. 3 Apparatus 3.1 Test dome, cylindrical and of the form shown in figure 1. The axial dimension of the dome is 1,5 D, where D is the internal diameter, and the test gas entrance is
3、on the axis at a distance D from the connecting flange and so arranged that the gas entrance into the dome is in a direction away from the pump mouth. The connection to the pressure-measuring gauge is at a distance 0,5 D from the connecting flange with its axis perpendicular to that of the dome. The
4、 axis of the test dome shall be perpendicular to the plane of the inlet flange of the pump. I I NOTE - For practical reasons the test dome is identical in form with that already adopted for the measurement of the volume rate of flow of positive-displacement pumps (see IS0 1607-l). Insofar as the mea
5、surement of ultimate pressure alone is con- cerned, it is not necessary to comply with the actual gas entry arrangement specified. The temperature of the dome shall be maintained within the limits 20 OC to 25 T. 3.2 Gauges, for measuring the ultimate pressure due only to non-condensable gases, calib
6、rated to an accuracy within + 5 % for pressures greater than or equal to 1 Pa, and within - + 10 % for lower pressures. The gauge shall be protected by a cold trap suitably designed and connected to ensure that the gauge is influenced only by the pressure due to non-condensable gases. 3.3 Vacuum gau
7、ges, for measuring the total ultimate pressure, of a type whose sensitivity is independent of the nature of the gas, or vapour, such as a diaphragm gauge. 1) 100 Pa = 100 N/m2 = 1 mbar; 133 Pa = 1 torr 1 Copyright International Organization for Standardization Provided by IHS under license with ISO
8、Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 04:41:00 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 1607-2 : 1989 (El The gauge shall be calibrated to an accuracy within + 10 % of the pressure to be measured. For this measurement a vapour
9、trap shall not be inserted in the connection line between the dome and the gauge. 4 Test method 4.1 Principle The method adopted is that in which the ultimate pressure is measured at a specified temperature, in a specified form of test dome attached to the inlet of the pump. 4.2 Procedure To commenc
10、e the procedure, the test dome shall be connected lo the inlet of the pump, after ensuring that the inner surface of the dome is clean and dry. Gauges (3.2 and 3.3) shall be connected to the test dome depending on the measurement being undertaken. If the dome is baked out prior to the measurements,
11、it shall, after having cooled down, be subjected for a few minutes to a pressure of at least 100 Pa by admitting dried ambient air. The gas inlet port of the dome shall then be closed. The pump shall be run with the prescribed quantity and grade of fresh oil, and at the rotational frequency specifie
12、d by the manufacturer. The ambient temperature shall be below 25 C unless otherwise stated in the conditions of test. After starting, the pump shall be operated with gas ballast for at least 1 h, and then without gas ballast for another hour. Thereafter, the pressure measurements shall be made at in
13、tervals of 30 min. The ultimate pressure is considered to be reached when three successive measurements show no further reduction in the measured pressure. The above test may also be carried out with full gas ballast (the gas-ballast valve being fully open). In this case the series of measurements s
14、hall not be commenced until the pump has reached its equilibrium temperature. 5 Test report All reports of test results shall indicate the exact nature and conditions of the test performed as enumerated below. 5.1 General conditions a) whether the results refer to the ultimate or that due only to no
15、n-condensable gases; b) whether gas ballast was in operation. 5.2 Supplementary conditions total pressure a) type and conditions of operation of all gauges used; b) type of seal and sealing material used on the pump inlet; cl type of traps employed, and their temperatures during the test; d) cooling
16、 water flow rate, if applicable; e) rotational frequency of the pumps; f) ambient temperature and pressure; g) specification of the pump oil. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale,
17、 04/27/2007 04:41:00 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 1607-2 : 1989 (E) Adaptor Gas inlet Pressure-measuring gauge connection -Pump inlet diameter Figure 1 - Test dome 3 Copyright International Organization for Standardization Provided by IHS under licens
18、e with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 04:41:00 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 1607-2 : 1989 (EI UDC 621.527 : 620.16 Descriptors : vacuum technology, vacuum apparatus, pumps, vacuum pumps, tests, performanc
19、e tests, pressure measurement. Price based on 3 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 04:41:00 MDTNo reproduction or networking permitted without license from IHS -,-,-