《ISO-1608-1-1993.pdf》由会员分享，可在线阅读，更多相关《ISO-1608-1-1993.pdf（7页珍藏版）》请在三一文库上搜索。
1、INTERNATIONAL STANDARD IS0 1608-I Second edition 1993-l 2-01 Vapour vacuum pumps - Measurement of performance characteristics - Part 1: Measurement of volume rate of flow (pumping speed) Pompes B vide B jet de vapeur - Mesurage des caractkristiques fonctionnelles - Partie 1: Mesurage du d - ejector
2、pumps; - booster pumps (i.e. pumps capable of operation in both the molecular and laminar flow regions, so combining the properties of diffusion and ejector pumps). These pumps may be with or without baffle(s) or trap(s). 2 Definitions For the purposes of this part of IS0 1608, the follow- ing defin
3、itions apply. 2.1 volume rate of flow; pumping speed: Under ideal conditions, the volume of gas which flows in unit time through the pump inlet. For practical purposes, however, the volume rate of flow (S) of a given pump for a given gas is, by con- vention, taken to be the quotient of the throughpu
4、t (Q) of that gas and the equilibrium pressure (p at a specified position in a given test dome, and under specified conditions of operation. Thus S = Q/P The units adopted for the volume rate of flow are the cubic metre per hour (m3/h) or the litre per second (I/s). For vapour pumps this form of exp
5、ression of volume rate of flow is considered to be valid only if p exceeds lop0 where p. is the ultimate pressure measured by means of the same gauge (see 3.2). 2.2 test dome; test header: A chamber of specific form and dimensions, attached to the inlet of the pump, through which a measured flow of
6、gas may be admitted to the pump, and which is equipped with means of pressure measurement. 2.3 ultimate pressure: Limiting pressure ak proached asymptotically in the dome, with the gas inlet valve closed and the pump in normal operation. 3 Apparatus 3.1 Test dome, cylindrical and of the form shown i
7、n figure 1. The axial dimension of the dome is 1,5D, where D is the internal diameter, and the test gas entrance is on the axis at a distance D from the con- necting 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-
8、measuring gauge is at a distance 0,5D from the connecting flange with its axis perpendicular to that of the dome. The axis of the test dome shall be perpendicular to the plane of the inlet flange (or inlet) of the pump. The internal diameter of the test dome shall be the same as that of the mouth of
9、 the pump, or of the inlet of any baffle or trap which may be incorporated. NOTE 1 If internal parts of the pump protrude beyond the flange (or inlet plane) of the pump, the reference plane is at the highest point of these internal parts and at this plane the pump mouth diameter is defined by the ar
10、rangement specified by the manufacturer. 3.2 Pressure gauge, calibrated to an accuracy of 1 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 03:54:01 MDTNo reproduction or network
11、ing permitted without license from IHS -,-,- IS0 1608-1:1993(E) f 5 % for pressures greater than or equal to 1 Pal) and of f 10 % for lower pressures. 3.3 Test gas Dry air shall be used unless otherwise specified. 3.4 Gas throughput measuring device The method adopted for measuring the throughput of
12、 gas will depend on the throughput required. The accuracy shall reach a) f3% for throughputs greater than 9,9 x 10-l Pa*m3/s; b) f5% for throughputs between 9.9 x 1 O- Pa-m3/s and 9.9 x 1 Om5 Pa-m3/s; c) f 10 % for lower throughputs. NOTE 2 Ideal gas behaviour at 20 “C is assumed. 4 Test method 4.1
13、Principle The method adopted is the “constant-pressure” method, in which the pressure at the mouth of the pump is intended to be kept constant during the measuring procedure. In practice, this condition is considered satisfied if the pressure measured in the test dome remains constant. 4.2 Procedure
14、 For measurement of the volume rate of flow, the test dome, pressure-measuring gauge and flowmeter shall be fitted to the pump as indicated in clause 3. For the purpose of the test, the pump shall be run with the prescribed charge and grade of fluid and at the heat- ing power specified by the manufa
15、cturer. The ambient temperature shall be kept constant to within f 1 “C, for the period of the test, in the range 15 “C to 25 “C unless otherwise specified. The test dome shall be evacuated when isolated from the gas inlet system until, over a period of 1 h, no further pressure drop is observed in t
16、he dome and the pump has reached its equilibrium operating temperature. Gas shall then be admitted into the dome in such a manner as to pro- duce the required measurement pressure (taken as an arithmetic mean of pressure gauge readings) and the system shall be allowed to reach a state of pressure eq
17、uilibrium before measurements are com- menced. The volume rate of flow (pumping speed) shall be measured, starting at the lowest pressure, point-by- point at different inlet pressures (at least five measurements within one power of ten, i.e. 1,6; 2.5; 4; 6,3 and 10 approximately). In the case of vap
18、our booster pumps, it is desirable to include a corm- sponding series of measurements commencing at the highest pressure. For each measurement point, the inlet pressure, ambient atmospheric pressure and the throughput of gas shall be determined. Inlet pressure and input flow of gas shall, as far as
19、possible, be measured simultaneously. If the meter- ing of the input gas takes more than 60 s, a pressure measurement shall be taken for each period of 60 s and the mean value recorded. If the highest and low- est readings differ by more than 10 %, the measure- ment shall be repeated. 5 Test results
20、 The relationship between the inlet pressure and the volume rate of flow shall be shown on a graph using a logarithmic abscissa for pressure, covering the range from the ultimate pressure up to atmospheric pressure, or such other range as may be appropriate to the design of pump, and a linear ordina
21、te for the volume rate of flow. The corresponding relationship between the inlet pressure and the throughput of gas shall be shown on a graph using a logarithmic ab scissa for the pressure and a logarithmic ordinate for the throughput. 6 Test report The test report shall include the following: a) b)
22、 cl 4 e) f) 9) t-d i) j) type and conditions of operation of all gauges used; type of gasket used on the pump inlet flange; type of any baffle(s) and/or trap(s) employed, and their temperatures during the test; maximum and minimum inlet and outlet tempera- tures, of vapour pump cooling water or refr
23、igerant, during the test; cooling water flowrate; type and quantity of vapour pump fluid; type and flowrate of backing pump, if used; heating power of the pump and limits of variation during the test; backing pressure and the type of gauge used to measure it; ambient temperature. 1) 100 Pa = 100 N/m
24、* = 1 mbar; 133 Pa = 1 torr 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 03:54:01 MDTNo reproduction or networking permitted without license from IHS -,-,- so 1608-1:1993(E)
25、 Dimensions in millimetres - Gas inlet Pressure-measuring I I I gauge connection Figure 1 - Test dome Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 03:54:01 MDTNo reproduction
26、or networking permitted without license from IHS -,-,- IS0 1608-1:1993(E) UDC 621.527.5:532.575.2 Descriptors: vacuum apparatus, vacuum pumps, steam jet pumps, tests, performance evaluation, flow 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 03:54:01 MDTNo reproduction or networking permitted without license from IHS -,-,-