AU593941B2 - Mass analyzer system for the direct detemination or organic compounds in ppb and high ppt concentrations in the gas phase - Google Patents

Description

COMMONWEALTH OF AUSTRA f PATENTS ACT 1952 COMPLETE SPECIFICATION FOR OFFICE USE: Class Int.Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority: Related Art: Tbm document contains tmmaWnd4imts made umnd Secteo 49.

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I I ,Name of Applicant: it Address of Applicant: COULSTON INTERNATIONAL CORPORATION AND GESELLSCHAFT FUR STRAHLEN-UND UMWELTFORSCHUNG mbH 1092 Madison Avenue, Albany, New York, 12208, United States of America and Ingolstadter Landstrabe 1, 8042 Neuherberg bei Munchen, Post Oberschleibheim, Federal Republic of Germany, respectively Friedhelm Korte, Ahmet Harun Parlar and Frederick Coulston .Actual Inventor: Address for Service: SHELSTON WATERS, 55 Clarence Street, Sydney domplete Specification for the Invention entitled: "MASS ANALYZER SYSTEM FOR THE DIRECT DETERMINATION OF ORGANIC COMPOUNDS IN PPB AND HIGH PPT CONCENTRATIONS IN THE GAS PHASE" The following statement is a full description of this invention, including the best method of performing it known to me/us:- 1 i lbi..;

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.1 ao MASS ANALYZER SYSTEM FOR THE DIRECT DETERMINATION OF ORGANIC COMPOUNDS IN PPB AND HIGH PPT CONCENTRATIONS IN THE GAS PHASE RELATED APPLICATIONS Thisiis a patent of addition application to Australian Patent Application No. 54894/86.

BACKGROUND OF THE INVENTION 1. Field of the Invention 0 The invention relates generally to the field of 10 mass analysis. The invention more specifically relates to a method and apparatus for gas-phase analysis of organic compounds at low concentrations in test samples.

2. Description of the Prior Art As is generally well known, problems associated with mass analyzers limit the range of concentrations over which organic compounds can be detected and analyzed in the gas phase. Test samples usually must *i be concentrated in an enrichment step prior to 20 analysis. Because complicated procedures for taking the sample and concentrating it cannot be standardized, considerable deviation and error in measurement occur. Considerable amounts of the test sample are lost by the use of gas sampling devices such as gas syringes for transfer of the concentrated sample to the analyzer. Additionally, gas phase reactions continue during transfer of the sample to the analyzer, further impairing the analysis. Very -lA-

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e .y ri iii~-i -a 9 *4 9 9* .9 9 9 20 99 9 *It 69 9erp *r 99 4lq 9*~ rarely is the detector satisfactorily combined with the sampling or reaction volume, and in such cases the systems are based on special spectroscopic methods.

Conventional mass analyzers cannot be used for the direct detection and measurement of organic compounds in ppb concentrations. The low signal-tonoise ratio at regular pressures of 10 4 to 10 6 torr prevents analysis in the ppb range. A straight increase in the vacuum reduces the concentration of the chemicals below the detection limit. These conventional mass analyzers include single-stage magnet sector units, and more recently introduced single-stage quadrupole units.

No practical device for directly analyzing chemicals in the gas phase in ppb concentrations was previously available which operated without a preliminary enrichment (concentration) step. For a mass analyzer using a single-stage magnet sector to obtain the required resolution and sensitivity, a very large magnet is required, resulting in a very massive machine. An alternative approach is to use two or more stages of magnet sectors or quadrupole units in which the first stage, in effect, provides a preliminary enrichment or concentration for the second step. Such multiple stage machines are more complicated and still tend to be physically large.

Their relatively large size and high cost generally preclude their use for on-site sampling or the continuous monitoring of industrial processes.

BRIEF SUMMARY OF THE INVENTION The primary object of the invention is to provide a method and apparatus for analyzing 2 c I ,r 1: chemicals in the gas phase at ppb and high ppt concentrations without a preliminary concentration step.

A specific object of the invention is to provide a single-stage quadrupole mass analyzer with increased sensitivity capable of detection even at pressures of 10 9 torr.

Another object of the invention is to provide a quadrupole mass analyzer of increased sensitivity with a more efficient device for transferring samples to the detector of the analyzer.

Yet another object of the invention is to prQvide an economical and portable mass analyzer of increased sensitivity for on-site sampling and continuous monitoring of industrial processes.

Briefly, in accordance with a primary aspect of 0 o0* the invention, the method comprises transferring organic substances from a storage vessel or reservoir at high pressure through a metering device into a quadrupole mass analyzer at low pressure, decreasing V the concentration of the substances by evacuating the mass analyzer to pressures below usual operating conditions, and detecting the substances with a Squadrupole mass analyzer of increased sensitivity.

A quadrupole mass analyzer is provided with a needle valve to permit the introduction of the sample into the vacuum chamber of the analyzer, an ion pump i for obtaining a reduced pressure in the vacuum a chamber, and a secondary electron multiplier for providing increased sensitivity.

Preferably the te t sample passes directly through a separator system of needle valves from a vacuum controllable sampling manifold to a modified quadrupole mass analyzer, the secondary electron multiplier is a Channeltron® electron multiplier, and 3 r a turbomolecular pump used during mass analysis is combined with a mass correction lens. These modifications to the system reduced background noise such that organic compounds could be detected and concentration determined in the range of from ppb to high ppt in the gas phase using direct mass spectroscopical analysis without preliminary enrichment procedures.

It has been found that the location and orientation of the gas inlet and outlet to the quadrupole mass sensing unit, and specifically the placement and aperture of the mass correction lens, have a critical effect on the detection limit.

°Although the precise mechanism for the improvement of 0* 4 the detection limit is not clearly undristood at this '.time, it appears to be related to an ongoing 0 cleansing of the quadrupole sensing unit during analysis which preferentially increases the duration which the molecules to be detected remain in the quadrupole sensing unit and thereby increases their concentration in the sensing unit relative to the population of the background molecules. This hypothesis is supported by the discovery that there are respective optimum areas of the aperture of the mass correction lens for various substances to be detected.

In any event, the improved performance is surprising in view of the fact that at low pressures the mean free path of the molecules is much greater than the physical dimensions of the quadrupole sensing unit, and normal non-linearties were previously observed at pressures above i 1 x 10 5 Torr. These normal non-linearities were i attributed to the molecular collisional effects and were previously minimized by operating the ionizer of 4- I

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the quadrupole unit at reduced electron emission current settings.

The effect of the aperture area of the mass correction lens and the variation of the optimum area for various substances are so striking that, in accordance with an important aspect of the present invention, the mass correction lens is provided'with means for variably selecting the area of the aperture for the specific substance to be detected. If the concentrations of a number of substances of varying molecular weights are to be determined, the aperture area is preferably reset a number of times during the mass scanning process to use respective optimum 6 values when scanning the fragment ions for the different substances.

During operaticn of the mass analyzer with the mass correction lens having an optimum aperture area, it was found that the noise level or baseline of the tc Charneltron® electron multipl.er deviated from its optimum minimum level as a function of the mass of the ions to be detected. In accordance with another aspect of the present invention, the operating characteristics of the Channeltron® are readjusted for the detection of ions of different mass. In particular, the value of the high voltage supplied to the Channeltron® for effecting electron multiplication is variably selected as a function of ion mass. This variable selection of the voltage supplied to the Channeltron® preferably is coordinated with automatic selection of the altenuator gain in the electrometer responsive to the direct Channeltron® output, so that the dynamic range of sensing the ion current of the selected mass is not exceeded. Associated with prestored Channeltron® voltage control settings are corresponding gain factors, and therefore the actual ion current is readily computed from the digitized electrometer output value, the prestored gain factor having been set for the mass being analyzed, and the electrometer altenuator gain having been automatically reset, if necessary, to avoid limiting of the electrometer output in the event of a high ion concentration at the mass selected for analysis.

Accordingly, this invention is useful for a variety of applications requiring the measurement of ppb and high ppt concentrations of chemicals. The invention was used for the determination of work Splace concentrations of chemicals in production units benzene and 1,2-transdichloroethylene, detection limit: 100-500 ppt), indoor concentration of chemicals of homes, offices etc. (pentachloro phenol, detection limit: 40-55 u g/m 3 analysis of *A water and soil samples (benzene from water, detection limit: 10 ppb, CO 2 from sand, detection limit: 100 ppt), determination of the photostability of organic compounds, determination of toxic compounds in S, inhalation chambers (acetylacetone, benzene, tetrachloromethane, freons 11 and 12, benzaldehyde, chlorobenzene, 1,2 transdichloreothylene, detection limit: 100-500 ppt). Also the invention can be used for the determination of blood alcohol, of volatile compounds in urine, of chlorinated hydrocarbons in fat tissues, of volatile products in sewage sludge, in slag of waste incineration, and in fly ash, for the monitoring of atmospheric concentrations of chemicals (pollutants such as NO x

SO

2 and organic environmental chemicals), of exhaust fumes of internal combustion machines, for the indentification and quantification of industrial gas phase reactions

NH

3 synthesis), of thermal degradability of raw -6i r 00 9 Q 0 00( 0fl 0 0 00 0 0 00 9.

00 00 *000 ,d materials used in the semiconductor industry, for the determination of gases such as hydrogen, helium, nitrogen and other gases in industry and for the monitoring of thermal decompositions of chemicals during combustion and pyrolysis.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which: FIGURE 1 is a schematic drawing of an apparatus according to a preferred embodiment of the invention including a vacuum controllable sampling manifold, and also showing an optimized mass analyzer, a special separator system, and a control and data system; FIG. 2 is a detailed drawing of the special separator system; FIG. 3 is a schematic drawing of the internal 20 construction of the quadrupole mass spectrometer unit including the electron multiplier; FIG. 4 is a schematic diagram of the mass filter in the quadrupole unit of FIG. 3; FIG. 5 shows respective graphs of the relative ion current intensities for benzene and trichloroethylene as a function of the area of the aperture in the mass correction lens; FIG. 6 is a schematic drawing of a control mechanism for automatic adjustment of the aperture of the mass correction lens; FIG. 7 is a schematic drawing of the optimized mass analyzer of FIG. 1 after the installation of the automatic control mechanism of FIG. 4 and an 7 7~ir

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00 0* o 0 9 *cr 9

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9 00 automatic control for variably selecting the operating voltage of the electron multiplier; FIG. 8 is a front elevation view of the optimized mass analyzer and microcomputer of FIG. 1 mounted on a cart to provide on-site sampling; and FIG. 9 is a rear elevation view of the system of FIG. 7 drawn to scale to illustrate the arrangement of the quadrupole sensor unit with respect to the sample inlet, ion pump, mass correction lens, and turbomolecular pump.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to FIGS. 1 and 2, there is shown a gas-phase mass analyzer system including a vacuum controllable sampling manifold 1 for obtaining a test sample in gaseous form, an optimized mass analyzer 2 for detecting minute concentrations of molecules, a special separator system 3 for controlled transfer of gas from the sampling manifold 1 to the mass analyzer 2, and a control and data system 4, all of which are further described below.

The sampling manifold 1 consists of a spherical reactor 5 with varying volumes of 1-400 liters (0.3- 110 gl.) and may include accessory devices for 00 *0 9 00 9 9~ 0 0000 0000 9 0y 8

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specific purposes such as a lamp 6 for irradiation.

The reactor 5 is equipped with a heating mantle 7 allowing temperatures of up to 200 0 C (400 0 The entire system 1 is evacuated by means of a turbomolecular pump 8 Galileo model PT-60) to a

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pressure of 10-8 torr. The exhaust of the turbomolecular pump 8 is removed by a fore pump 9 Edwards model E2 M8). The reactor 5 can be separated from the pump system 8, 9 by a sliding valve 9' with viton seals.

In a typical mode of operation, solid or liquid samples are introduced into an inlet system After achieving the desired pressure in the inlet system 10, the samples or portions thereof become vaporized. The concentrations in the gas phase can be determined by measuring the pressure. The inlet system 10 consists of a stainless steel casing with vacuum-tight sealable openings. A spring-loaded metal rod 11 serves to liberate mechanically volatile samples kept in standardizable glass capillaries.

Porcelain boats are available for the introduction of solid samples. Placed underneath the inlet system a commercially available combination of variable gas valves 12 CJT-Vacuum-Technik, Ramelsbach) controls the flow of material into the reactor The sampling manifold 1 may be used at pressures within the range of of 1-10-8 torr and also works with variable volumes of gas mixtures at variable pressures.

The optimized mass analyzer system 2 consists of a quadrupole mass spectrometer unit 13 (UTI model 100c-02) including a Channeltron® electron multiplier 14. The quadrupole mass spectrometer unit 13 is further described in the "UTI100C Precision Mass Analyzer Operating and Service Manual", Uthe 1k t t t& L Vi 9 Technology International, 225 North Mathilda Avenue, Sunnyvale, California 94086 (1979), which is incorporated by reference herein. The UTI100C unit 13 is sold along with a control unit (76 in FIG. 8) which enables manual operation and provides an interface for direct connection to a standard microcomputer 4 which provides the control and data system. Without the modifications described below, the UTI100C was found to have a detection limit for nitrogen of 10-14 torr or 0.1ppm.

In accordance with an important aspect of the invention, the quadrupole unit 13 was further optimized by installing an ion pump 16 Varian Vaciono 8 1/s) at a right angle, a mass analyzerturbomolecular pump 17, and a mass correction lens installed at the inlet of the turbomolecular pump.

The mass correction lens is a copper disc having an outer diameter of 48mm, a thickness of 2mm, and an aperture of from about 20mm to 45mm which should be selected for the particular substance to be detected, as further described below. The exhaust of the turbomolecular pump 17 is eliminated by an associated fore pump 17'.

The optimal functioning of the modified system was evaluated according to the following criteria: Tightness of the entire system was determined by means of the time dependent increase of pressure allowing a maximum leak rate of lxl0 5 torr 1/s; and Sensitivity measurements of the quadrupole spectrometer 13 were made using benzene, acetylacetone and chloroform, achieving a detection 3 limit of at least 100 ppb.

By these improvements, the operating pressure of the mass analyzer was reduced to 10 9 torr, so that 10 S'i N k the background noise could not be measured any longer. Since the sensitivity increased enormously, the detection and determination of ppb and ppt concentrations of chemicals was made possible. Since the background could not be measured, spectras from pure samples were obtained.

The separator system 3 is placed between manifold 1 and mass analyzer system 2, and an optional selector valve 21 may be placed between the separator system 3 and the sampling manifold 1 to obtain gas phase samples from locations (not shown) other than the sampling manifold 1. The separator system 3, further shown in Fig. 2, consists of three Sneedle valves 18-20 which can be combined in parallel 4 or in series. Usually valve 18 is closed, the pressure in the manifold is higher than 10-6 torr and the concentrations of the chemicals to be examined are high. Valves 19 and 20 control the flow into the mass analyzer 2 in such a way that the necessary levels for both pressure and concentration of the Pr materials in the mass spectrometer are achieved. In case these operating parameters exist already in the manifold 1, the manifold 1 and mass analyzer system 2 can be connected directly via valve 18.

A control and data system 4 (Fig. 1) uses a "Texas Instruments Portable Professional" microcomputer for interpretation and storage of information about the state of the system. The i microcomputer includes a TMS 9995 microprocessor board (16-bit microprocessor with 8-bit data bus, 73 commands, 3.0 MHz system frequency, floppy disc control RS 232c, 64 K byte storage, double Euroboard format), an RS 232 input board (single Euroboard format), an input board (16 bit, single Euroboard format), an output board (16 bit, single Euroboard 11 S- 1 -4 512, single Euroboard format), a first D/A converter board (12 bit resolution, single Euroboard format), a second D/A converter board (16 bit resolution, single Euroboard format), an E-Bus back wall board (single Euroboard format), a power supply +-15 V with overwattage protection and current limiter), a highresolution color monitor, a system chassis, a VT-100 compatible keyboard, a dual-Floppy-Disk-DSDD, an interface cable for the UTI-100c-02 quadrupole spectrometer 13, and a housing for the processor and monitor.

The microcomputer was programmed to perform S* remote control of the UTI-100C-02 quadrupole spectrometer scanning and collection of the spectrometer data. The computer program is listed in the Appendix to the present specification.

at The microcomputer 4 transmits a precise voltage to the spectrometer 13 to select the mass of the ions which are detected by the electron multiplier 14.

This precise voltage is generated by a 16 bit digital-to-analog converter having a 0-10V range, a dynamic impedance less than 1 kOhm, noise level less than ImV, and drift less than 0.0005%, to insure a spectrometer resolution of 0.01 AMU. The microcomputer also has an output for selecting whether the electron multiplier is reading a multiplied ion concentration signal or a nonmultiplied Faraday cup signal received for determining the multiplier gain by comparison of the two signals, and an output activating an analog switch for feeding either the signal from the electron multiplier or the signal from a pressure gauge to a twelve bit analog-to-digital converter for input to the microcomputer. In this fashion the 12

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0o 55 microcomputer can read the electron multiplier for ion current within the picoammeter range from 10 5 to 10-12 amperes, and the total pressure from 10 3 to 10-8 torr. The ionizer filaments in the mass spectrometer are automatically shut down in the event of extreme conditions such as loss of vacuum indicated by the electron multiplier signal or the pressure gauge signal.

The microcomputer can therefore control the mass spectrometer to scan any desired range or discrete points of the mass spectrum. The microcomputer has also been programmed to present the spectrometer data acc.ording to several standard formats. Scans are performed prior to analysis to characterize background noise as a function of total pressure and this pre-determined background noise level is subtracted from the molecule or fragment ion concentration taking into account continuous total pressure monitoring during analysis. The total pressure is continuously displayed on the monitor.

The molecule concentrations are also normalized taking into account the total pressure in order to display normalized line spectra on the monitor or to output the mass spectra to a printer as listings or (graphic) matrix reproduction. The intensity of freely selectable peaks can be monitored as a function of time. The peak intensity can be transmitted in serial RS 232 format to a remote location. The microcomputer can perform specific peak-mode monitoring of a maximum of eight selected AMU peaks as a function of time. The spectra can be automatically calibrated for m/c and their intensities. Quantitation is performed using both second-order approximation and suitable calibration substances Freons, carbon tetrachloride,

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13 >4 benzene, tcluene). Moreover, specified standard spectra can be stored using five selected fragment ions.

The following suggested applications illustrate the various fields of application for our mass analyzer system, but they are in no way intended to limit the uses or fields to which this invention is capable of being applied: 1. Determination of work place concentrations of organic chemicals in production units By means of our mass analyzer system, the concentrations of chemicals in factories and production units can be determined and controlled u continuously. The optimized analyzer system 2 with the separator system 3 is able to measure directly air samples taken at ambient pressure. By using the separator 3 with the optional selector valve 21 (Fig. samples from different locations can be taken. Since one spectrum only takes 10 seconds, the time dependent work place concentration at different '9 locations can easily be determined and monitored.

1 t Also, acute maximum concentrations, which are extremely important for the evaluation of work place *safety, can be measured. Chemical concentrations of benzene and 1,2-transdichloroethylene, for example, can be detected to 100-500 ppt.

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t 2. Determination of indoor concentrations of chemicals Since the sensitivity of the described gas phase mass analyzer reaches the low ppb to high ppt level, the concentrations of pollutants in indoor areas, e.g. homes or offices, can easily be measured.

Concentration/time diagrams allow the elucidation of the actual indoor exposure to pollutants.

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I I- I3 e 4 Sr 0 04 4 04 Pentachlorophenol, for example, can be detected down to 40-55 pg/m 3 3. Analysis of aqueous and solid samples (studies of water and soil samples) After placing aqueous or solid samples into the inlet system 10, the volatile compounds are transferred into the gas phase by the high vacuum and analyzed in the way described above. CO 2 from sand, for example, has been detected by means of our invention at 10 ppb, and the detection limit is about 100 ppt.

4. Determination of the photostability of organic compounds The material to be examined is placed on a suitable carrier on a cold finger by dissolving the material, applying on the cold finger, and evaporating the solvent or placing the material directly on the cold finger, e.g. plastic foils) and irradiated by external light sources 5 with variable 20 wave lengths. The volatile photoproducts are determined by the mass analyzer system, the concentrations are determined by measuring the pressure.

5. Monitoring of inhalation experiments Our analyzer can be used particularly well for the monitoring of toxicological inhalation studies, since both the administered chemicals and the substances exhaled by the animal can be measured over any desired period of time. Acetylacetone, benzene, tetrachloromethane, freons 11 and 12, benzaldehyde, chlorobenzene, and 1,2-transdichloroethylene, for example, can be detected down to 100 to 500 ppt.

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t Turning now to FIG. 3, there is shown a schematic drawing of the internal components of the UTI100C mass spectrometer unit 13. At the bottom is an ionizer 131 in which a thoriated irridium thermionic filament 132 emits electrons which are attracted to a cylindrical grid 133, pass through it, and form a negative space charge region 134 within the grid 133. Some of the electrons strike molecules in the gas sample, causing them to ionize, and the ions are attracted to the negative space charge region 133. The grid 133 is itself positive, causing ions to be emitted through a central aperture in a focus plate 136 and travel upward to the Channeltron electron multiplier 14.

iIn order that ions of only a selected mass reach the Channeltron® 14, a mass filter generally designated 137 is interposed between the ionizer 131 and the Channeltron® 14. The mass filter 137 includes four precisely machined rods 1.38, two of which are charged positive and the other of Swhich are charged negative setting up a quadrupole electric field 139, as shown in FIG. 4.

This quadrupole electric field 139 has a value of zero on axis, and increases from zero as a function of the distance from the axis, tending to cause the ions to move away from the positive rods and toward the negative rods. But ions of a selected mass, or more precisely a selected mass to charge ratio, are diverted by an additional alternating potential (Vlcoswt, V 1 sinwt) between the positive and negative rods, causing the selected ions to travel about the axis in a circular orbit, and thereby permitting them to travel to the Channeltron® where they are detected as an ion current.

16

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of the ditacefr eaxs edigoaueh ionsto mve way rom he ositve rds nd twar th neatie ros. ut ons f aselctedmas, o moepeieyaslce ast hrerto r 0C 0O 00 0*4C 00 8 O* 0 o 00 00 0 0 00 00 A simplified model of the operation of the mass filter assumes that the resonance condition of the selected ions results from a centripetal acceleration which is known from Newton's law to be related to the electrostatic force according to: mrw 2 q Er where w is the mass of the selected ion, r is the radius of the centripetal motion about the central axis of the mass filter, w is the angular frequency of the alternating potential (Vlcoswt, Vlsinwt), is the charge of the ion, and Er is the maximum radial component of the alternating electric field at the radius r. The maximum radial component E r however, is approximately a linear function of r, according to: E r r 2 a where a is a constant distance on the order of the radius of the rods 138 from the central axis and which is related to the diameter and spacing of the rods. By eliminating Er from the two equations above, it is seen that the resonance condition becomes independent of r, and the selected mass to charge ratio can be varied by adjusting V or w: m V q w 2 a 2 In practice it is most convenient to adjust V while holding w constant, to obtain a mass spectrum.

This simplified theory of operation does not take into (,ccount the effects of collisions between ions or ions and molecules which might occur in the 17 V: t rf r sj j t mass spectrometer unit 13 and tend to disturb the highly selective resonance condition. Although the low pressures in the unit during mass analysis insures that intermolecular collisions are infrequent, they are manifested by the so-called normal non-linearities which appear at pressures greater than about 1 x 10 5 torr. These effects have previously been minimized by operating the thermionic filament 132 (FIG. 3) at reduced emission currents.

Apparently this reduces the normal non-linearties by reducing the ionization rate in the ionizer, so that nonlinear effects caused by ion-ion interactions (such as inter-ion collisions or the build-up of an ion space charge in the mass filter 137) are reduced.

Experimentation with the UTI100C, however, revealed that the placement and orientation of the inlet and pumps had a critical effect on the mass spectrometer's detection limit. Apparently these factors affect the detection limit by preferentially affecting the flow of the background constituents

N

2 in an air sample) relative to the ions to be detected, and also tend to shield the highly sensitive Channeltron® from interference, which would otherwise be caused by the flow of the sample toward rather than away from the Channeltron® if the vacuum pumping system is kept on during sensing to preferentially deplete the background concentration.

In any event, it has been found that the detection limit can be greatly increased by introducing the sample from a central side port in the UTI100C mass spectrometer unit 13, and evacuating the unit from its ionizer end with a turbomolecular pump during mass analysis. Also, the ion pump (16 in FIG. 1) should be used to reduce the partial pressure of the light molecules in the mass spectrometer unit 18 13 prior to the introduction of the sample, although it cannot be used during the subsequent mass analysis of the sample since its power supply generates electrical interference with the electrical signal from the Channeltron® 14. Moreover, it is very advantageous to use the mass correction lens (15 in FIG. 1) at the inlet to the turbomolecular pump 17, and to select the area of the aperture in the lens in accordance with the mass of the molecules to be detected.

Turning now to FIG. 5, the criticality of the area of the aperture of the mass correction lens is illustrated along with the dependance of the optimum S* 0 aperture area as a function of mass of the molecules to be detected. The relative intensity of the detected ions as a percentage of the maximum ,t intensity is plotted as a function of the relative 4 t aperture area, in terms of the percentage of the maximum aperture area for a full opening having a 45mm internal diameter for the compound trichloroethylene (curve 45). The optimum aperture area for benzene is about 54% of the area of a full opening an internal diameter of 33mm). The optimum aperture area for trichloroethylene, however, is about 42% of the area of'a full opening an internal diameter of about 29mm).. In each case the pressure during mass analysis was 2.2 x 10-6 toi:r.

In view of FIG. 2, it is advantageous to provide means for automatically selecting the aperture area during mass analysis to optimum areas for each compound to be detected. For this purpose a photographic iris diaphram was installed in lieu of I the 2mm thick copper disc mass correction lens (15 in FIG. Therefore, the curves as shown in FIG. 2 can be obtained by continuously varying the area of 19

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the aperture and noting the change in the ion current for a characteristic ion of a standard sample of the compound to be detected. Preferably these tests are run for a number of different compounds, and the optimum values are prestored in the memory of the microcomputer 4. Then, during analysis of a sample, they are recalled from memory for readjusting the aperture area before the scanning of each of the respective fragment ion masses of interest.

Preferably the system is provided with automatic means for adjusting the aperture area of the mass correction lens. A proposed device is shown in FIG. 6. The iris diaphram 51 is mounted inside a S• *two-part vacuum housing 52 which is provided with studs 53 or holes for attachment of the housing to the standard flanged vacuum connections see *9 4 FIG. A ring gear 54 mounted to the iris diaphram 51 is adjusted by a worm gear 55 attached to a 00 control shaft 56 protruding from the housing 52 through a vacuum seal 57. A second ring gear 58 is attached to the control shaft 56 and is selectively rotated by a servomotor 59 via a worm gear 60 for adjustment of the iris opening. The shaft of a multi-turn potentiometer 61 is coupled to the control shaft 56 in order to sense the degree of opening of the iris diaphram 51.

In order to provide automatic as well as manual adjustment of the iris aperture, the servomotor is driven by a servo error amplifier 62 responsive to a command signal on a line 63. The command signal is ,a provided either by a manually set potentiometer 64, or by a digital-to-analog converter 35 driven by an output interface 36 coupled to the microcomputer 4, as selected by a switch 43.

20- 1.

The optimized analyzer 2' with the automatic aperture adjusting mechanism installed is shown in FIG. 7. When the aperture 31 of the adjustable mass correction lens 15' is preset to a new area for a new substance as commanded by the computer 4, it is also desirable to automatically adjust the multiplier voltage of the Channeltron® electron multiplier to preselected values which optimize the signal-to-noise ratio of the detection process for the ions corresponding to the substance. For this purpose a control unit 38 adjusts the regulator 39 of the Channeltron® power supply in response to a control signal. A switch 40 is provided to obtain the control signal from either another digital-to-analog o* converter 38 driven by the output interface 36, or S. from a manually adjustable potentiometer 42.

Turning now to FIGS. 8 and 9, there is shown a scale drawing of a mobile version of the optimized mass analyzer 2 of FIG. 1 mounted on a cart 70 having a frame of which is 32" high, 24" wide, and 32" 1 deep. Instead of the sampling values of FIG. 2, there is provided a flanged sample inlet 71, and a variable leak valve 72 (Series 203 by Granville- Phillips Co. of Boulder, Colorado) having a digital readout 73 indicating a multitude of possible settings. To quickly shut off the inlet flow, an inlet valve 74 is placed in series between the variable leak valve 72 and an inlet pipe 75 attached to the UTI100C mass spectrometer unit 13. (See the back side in FIG. 9).

The controls for the system 2 are shown in FIG.

9 on the front of the cart. The mass spectrometer unit 13 is controlled by a UTI control console 26, which indicates the ion mass being scanned in AMU and the vacuum in the spectrometer unit in torr. (The 21 l i I li-~ vacuum is sensed from the electrical conditions in the ionizer 131 in FIG. The alternating voltage for the mass filter (137 in FIG. 3) is provided by an RF generator 77 by the Uthe Co., but it does not have any operator-adjusted controls. The control console 76 also provides the power supplied to the Channeltron®, which was supplied by the Uthe Co. The ion pump 16 is powered by an ion pump control unit 78. The ion pump is a Varion No. BL/S No. 911-505 with a magnet No. 911-0030, from Varion Co., 700 Stuttgart 8, Handwerk str. 5-7, West Germany. The ion pump control unit is part No. 929-0062 supplied by Varion.

The turbomolecular pump 17 is an Electronana model ETP63180 controlled by a control unit 79 model No. CST-100 distributed by Vacuum Technik GMBH, 8061 Ramelbach, Asbacherstr. 6, West Germany. The c" turbomolecular pump 17 is run continuously at 6,000 RPM and is cooled by a heat sink 79 and a fan To prevent backflow of lubricating oil mist, an in-line filter 84 (Model No. TX075 by MDC Vacuum Products Corp., 23842 Cabot Blvd., Haward, Calif.

94545) connects the turbomolecular pump 17 to its associated fore pump 17'. The fore pump 17' is part No. ZM2004 supplied by Alcatel Co., 7 Ponds St., Hanover, Mass. 02339.

To reduce vibration to the mass spectrometer unit 13, the turbomolecular pump 17 is mounted to the cart 70 via four rubber mounts, type SLM-1 supplied by Barry Controls GmbH, D6096 Raunheim, West Germany. The mass spectrometer unit is also more directly mounted to the top of the cart via rubber mounts 82 and a beam 83 which is clamped to the outer shell of the mass spectrometer unit 13.

22 In order to initially put the optimized mass analyzer in a high vacuum state, the fore pump 17' is turned on to pump the system down to a low vacuum.

Then the turbomolecular pump is turned on until a higher vacuum is obtained. The system is then "baked out" by turning on a "heat wrap" resistance heater which is energized by a triac power control 86 to bring the mass spectrometer unit 13 up to between 200 0 C to 320 0 C. The "heat wrap" 85 and triac control 86 are supplied by CJT Vacuum, 8061 Ramelbach, Asbacherstr 6, West Germany. After the system is sufficiently baked out to obtain a high vacuum better than 10 8 torr), the ion pump 16 is turned on to obtain an ultra-high vacuum better than 9 torr.

Prior to analysis, power to the heat wrap 85 is turned off and the spectrometer unit is allowed to cool for about one to two and a half hours (depending I rot on the bake-out temperature) to a final temperature of 150 0 C or lower. For analysis, the ion pump 16 is turned off and then the mass spectrometer 13 is switched on from the UTI control console 76, thereby energizing the RF generator 77, the ionizer filament (132 in FIG. and the high voltage supply to the Channeltron® electron multiplier 14. The computer 4, and its associated printer 87, may be turned on at this time for automatic rather than manual control of the mass spectrum scanning.

For analysis of a sample from a source, the source is connected to the sample inlet 71. After checking the numeric indicator 73 to ensure that the I', variable leak valve 72 is closed, the inlet valve 74 is opened. Then, the variable leak valve is slowly opened until a pressure of 10 6 to 10 7 torr is indicated on the control console 76.

-23i6i At this time a constant stream of the substances to be analyzed is passing through the mass spectrometer 13 to the turbomolecular pump 17, and the mass analysis process may begin for scanning a range of mass values, or if scanning for determining the concentration of known substances, the discrete mass values of the characteristic fragment ions of each substance. Although a mass correction lens having a fixed aperture area is shown in FIG. 9, if the variable aperture lens 15' of FIG. 6 were used, the aperture of the lens would preferably be readjusted to an optimum area for each known substance. The total intensity of each known substance to be determined is then obtained by a weighted average of the measured currents of its fragment ions, the weighing factors being determined by the relative intensities of the fragments obtained during analysis of a standard sample of the substance .to be determined, with appropriate correction for 20 fragment ions which are common to more than one of the known substances.

The scanning process with the analyzer 2 of FIGS. 8 9 requires approximately 2 minutes for S".scanning a mass spectrum ranging from 0 to 300 AMU.

After scanning is done, the ion pump 16 is turned back on. At night, the heat wrap 85 is turned on, for example, by a diurnal timer, so that it will have $toobaked out the system at night and the system will have cooled to operating temperatures in the morning.

S 30 To service the ion pump 16 and the turbomolecular pump 17 without breaking vacuum to the spectrometer unit 13, respective gate valves 88, 89 are provided for manually closing off the connections of the pumps to the spectrometer unit. The gate valves 88, 89 are Model No. SVB 1.53VM supplied by Torr Vac. Products, Van Nuys, Calif.

24

L.

jA In view of the above, an economical and portable mass analyzer has been described which uses a quadrupole mass spectrometer of increased sensitivity. A high sensitivity electron multiplier is used along with a mass correction lens arranged with respect to a sample inlet and a vacuum source so that the detection limit is greatly improved for the substances to be detected. Preferably the aperture area of the mass correction lens is variably adjustable and is set to a perdetermined optimum area for each substance under analysis. It is also preferred to adjust the electron multiplier high voltage value to a predetermined value for each ion mass to optimize the signal-to-noise ratio of detection. The small size and low cost of the mass i .analyzer enables it to be used economically for onsite sampling and monitoring or controlling •industrial processes.

'4 t Sft *2

APPENDIX

MASS SPECTROMETER CONTROL PROGRAM4 FOR THE TEXAS INSTRUMENTS PROFESSIONAL COMPUTER BASIC VERSION 1.10 Copyright 1986 Coulston International Corp. aqd Gesell1schaft Fur Strahien-Un d Umwelt torschung mbH ILIST 2RUN 3LOAD" 4SAVE" 5F'ILES 6CONT 7,11LPTI 8LOCATE 9COLCIR JoFALET

BKORND

Ok

LOAD'GSF

Ok

LIST

KEY OFF 6 CLEAR DIM LIV.(303) DIM PKSEL(16, 16) DIM RANGED( 13) DIM AVALUE(301,3) 31 DIM X(300) DIM TOP( 13)

CLS

0051)5 3000 INITILIZE COLOR 2 LOCATE 1,10 K-41 GOTO 500 MASTER MEi4U 500 REM SUBROUTINE MASTER 505 CLSIKEY OFF 510 LOCATE 3,23 515 COLOR 0,2,0,64 520 PRINT t ILIST 2RUN 3LOAD' 4SAVE" 5F t r LES LsCCNT 7, "LPTI SLOCATE 9COLOR IQPALET I 515 S520 S 525 530 'ff 535 540 ii f 545 550 555 560 565 3. 70 575 580 585 590 605 6,10 615 620 4 625 625 4 ILIS COLOR 0,2,0, 64 PRINT SYSTEM MENU COLOR 6,0,0,0 LOCATE PRINT "Fl Reeid Spiectrum'; LOCATE PRINT "F2 Save Spectrum, LOCATE 10,5 PRINT "F3 Road Total Pressure;1 LOCATE 12,5 PRINT "F4 Display Background"; LOCATE 14,5 PRINT 11F5 Time Scan"; LOCATE 16,5 PRINT "PF6 Print Routines'; LOCATE 6,40 PRINT "F7 a Calibrate";1 LOCATE 8,40 PRINT F8 aS View Spectrum";, LOCATE 10,40 PRINT F 9 Initilize Diskette LOCATE 12,40 PRINT "Flo Standby PRINT "Flo Standby T 2RUN 3LOAD"1 4SAVE"1 5FILES 6CONT 7, "LPTI SLOCATE 9COLC'R 615 PRINT 11 F9 Inltilizo Dlsket'e 620 LOCATE 12,40 625 PRINT "F10 Standby "i 630 LOCATE 14,40 63V PRINT "P11 w Identify Spectrum"l.

640 LOCATE 16,40 645 PRIN'r "P'12 w Exit to System"I LOCATE 24,40 655 COLOR 560 PRINT toSelection ->";S:PRINT cHR*(219); 665 REM LOCATE 1,1,0'PRINT 670 KEY I "A" It 675 KEY 2,"B" 680 KEY 3,'C" 685 KEY 690 KEY 695 KEY 6,"F" 700 KEY 705 KEY 8,"H" 710 KEY 9,"1" 715 KEY 720 KEY l1,"K 725 KEY 12,"L" 730 1LIST 2RUN 3LOAD" 4SAVE' SFILES 6CONT 7, 'LPTI SLOCCATE 9CCLCIR 1OPALET 730 IF RIOHTS(TIME*,2) RIGHTS(TEMES,2) THEN 745 ELSE 735 735 LOCATE 1,32,01COLCR 4,0,0,OIPRINT"TIME-------':LOCATE 1,

TIMES

7.45 CMD*-INKEYSIIF CMOS-"" THEN GOTO 730 750 IF CMOS THEN COTO 810 755 IF CMOS THEN GOTO 835 760 IF CMOS THEN COTO 855 765 IF CMS THEN COTO 875 770 IF CMOS THEN GOTO 895 775 IF CMOS THEN GOTO 920 780 IF CMOS THEN GOTO 940 785 IF CMOS THEN GOTO 965 790 IF CMOS THEN COTO 985 795 IF CMOS THEN GOTO 1005 900 IF CMOS THEN GOTO 1020 805 IF CMOS THEN GOTO 1035 806 COTO 500 810 REM READ A SPECTRUM 815 COLOR 7,01LOCATE 24,57IPRINT "F1" 820 GOSUD 1500 825 COTO 830 REM 835 REM SAVE SPECTRUM 840 ILIST 2RUN 3LOAD" 4AVE" 5F.ILES 6CONT 7,"LPT1 SLC 42:PRINT TIME$:TEME$= qO *4 )CATE 9COLOR .9 840 845 850 tr 855 ttte 860 865 866 867 870 t"t. 875 c~r 880 885 887 890 895 900 905 910 915 920 925 930 935 940 COLOR 7,01LOCATE 24,571PRINT "F2'g GOSUB 10000 COTO REM REM READ TOTAL PRESSURE COLOR 7,OILOCATE 24,57sPRINT "F31; GOSUB 7500 OUT FUNC, CONSOLE+FIL+MULT COTO 730 REM REM DISPLAY BACKGROUND COLOR 7,01LOCATE 24,57:PRINT "F4" 1 GOSUB 26000 COTO 45 REM REM TIME SCAN COLOR 7,OULOCATE 24,57ZPRINT "FS" 1 OOSUD 14000 COTO 45 REM PRINT SPECTRUM COLOR 7,OiLOCATE 24,57IPRINT "F6"; GOSUB 13000 COTO

I

ti ILST 2RUN 3LOAO" 4SAVE" 5FILES 6CONT 7,"LPT1 9LOCATE 'COLOR I OPALET 940 REM 945 REM CALIBRATE A2 4i ~Y .4 I t, I 950 COLOR 7,O:LOCATE 24,57:PRINT "F7" 955 GOSUD 24000 960 GOTO 945 REM 970 REM VIEW SPECTRUM 975 COLOR 7,0,LOCATE 24,571PRINT "F"1 977 GOSUB 10200 980 GOTO 985 REM 990 REM INITILIZE DISKETTE 995 COLOR 7,OILOCATE 24,57:PRINT "F9"- 996 GOSUB 9000 1000 GOTO 1005 REM 1010 REM RESERVED 1015 COLOR 7,01LOCATE 24,57:PRINT "PLO"I 1020 REM 1025 REM RESERVED 1030 COLOR 7,0ILOCATE 24,57:PRINT "P11"; 1032 GOSUB 40000 1033 GOTO 1035 REM 4* ILIST 2RUN 3LOAD" 4SAVE" 5FILES 6CDNT 7,"LPT1 8LOCATE 9COLODR 1 OPALE'r Pe I I It t It 1035 REM 1040 REM EXIT TO SYSTEM 1045 COLOR 7,01LOCATE 24,57:PRINT "P12"; 1050 CLS 1055 EN$CHRS(13) 1060 KEY 1,"LI*ST 1065 KEY 2,"RUN"+EN$ 1070 KEY 3,--LOAD+CHR$(32)+CHR$(34) 1075 KEY 4,"SAVE"+CHR$(32)+CHR$(34) 1080 KEY 1085 KEY 6,"CONT"+ENS 1090 KEY 7,","+CHR*(34)+"LPT1" 1095 KEY 8,"LOCATE 1100 KEY 9,"COLOR 7,0,0,0" 1105 KEY 1110 COLOR 7,0,0,0 1115 KEY OFF 1120 SYSTEM 1500 OOSUB 110001 PRINT HEADER 1735 OOSUB 8921 'LOAD AVALUE(X,O) WITH BACKGROUND 1740 FOR E-ASrART TO AEND 1750 OOSUB 6000 BUMP THE AMU 1752 COLOR 4,0:LOCATE 1,42,0:PRINT TIME$ 1752 COLOR 4,OILOCATE 1,42,OIPRINT TIME$ ILIST 2RUN 3LOAD" 4SAVE" SPILES 6CONT 7, 0 AND COLLECT VALUES "LPT1 SLOCATE 9COLOR 1752 1753 1760 1770 1780 1790 1800 1810 1820 1850 2000 2001 2002 2010 2020 2025 2030 2035 2040 2080 2100 COLOR 4,O3LOCATE 1,42,0:PRINT TIMES LOCATE 3,228PRINT R GOSUD 2000 READ IT GOSUD 4000 PLOT IT NEXT E GOSUD 7700 ZERO THE DAC AS-!NKEYSIIF THEN LOCATE 1,42UPRINT TIMES:GOTO 1800 IF ASC(AS)<>13 THEN DEEPaGOTO 1800 EFLAO-I1

RETURN

SUBROUTINE TO READ AMP/TORR METER IF R>12 THEN R-12 IF R(5 THEN R=S OUT RANOE,RANOEDeR) IF AIT=O THEN GOTO 2040 FOR Al TO 1000 NEXT A AITmO FOR DEL-I TO 300:NEXT DEL WAIT &H208,254,255 STATUSmINP( &H208 OVERRANOE-SON(STATUS AND 2-2) i\i 2120 IF OVERRANGEUI THEN COTO 2530 2140 WAIT &H208,254,255 2160 DIOITOlwINP(&H2O5)s0 2180 IF OK-0 THEN COTO 2140 2200 WAIT &H208,254,255 2220 DI0IT02-INP(&H2O5):0K=S0N(DIGITO2 AND 2^6) 2240 IF OK-0 THEN COTO 2200 2260 WAIT &H208,254,255 2280 STATUSINP(&H208) 2300 DIGIT03-INP(&H205):OK-SGN(DIGITO3 AND 2^7) 2320 IF OK-0 THEN COTO 2260 2340 OVERRANOE-SON(STATUS AND 2^2) 2360 IF OVERRANGE-1 THEN GOTO 2470 2380 DIOITlA-IS AND DIGITOI 2400 DIOIT2AwI5 AND DIGIT02 2420 DIGIT3A-15 AND DIGITO3 2440 VALUE-DIGITIA+(DIGIT2A *.I)+(DIGIT3A *.01) 2460 REM IF CHECK=0 THEN GOTO 2500 2470 IF VALUE<.8 AND VALUE=0 THEN R-R+1IZF R=13 AND VALUE<.G THEN 2500: IF R=13 T HEN 2500OAIT-Ii30TO 2000 2480 IF VALUE>9.5 THEN R-R-I:AIT=I:GOTO 2000 2490 IF VALUEwO THEN R-R-21AIT-IIGOTO 2000 2500 AVALE(E,1)-VALUE 2515 AYALUE(E,2) 2520 COTO 2570 2530 'VALUE-9.99 2530 'VALUE9.99 2540 REM BEEP 2550 IIT-1 2560 COTO 2460 ve.. 2570 RETURN 3000 REM 3020 REM 3040 REM 3060 I/0 of 3080 3100 LET FUNC-&H206 OUTPUT CHANNEL 0206 "FUNCTION' 3120 REM 3140 LET EXT-2 DI IHOLD DATA 0 3160 LET KV3-4 D2 IACTIVE 0 3180 LET FIL8 D3 0= FILAMENT QFF(NEED PULL-LIP) 1 ft 3200 LET TP-16 D4 1=SELECTED 0 3220 LET MULT-32 DS 1=SELECTED 0 3240 LET FAR64 D6 1=SELECTED 0 3260 LET CONSOLE=i28 D 07 0=CONSOLE CFF(NEED PUILL-IP) 3280 LET K-41 3290 TOP(4)=10000! 3300 LET AIT-O 3301 TOP(5)-100000! 3302 TOP(6)-000000! 3303 3304 TOP(8)-IE+08 3305 TOP(9)-IE+09 3306 TOP(10)-IE+10 3307 TOP(1)-IE+1 3308 TOP(11)-IE+11 3309 TOP(12)inE+12 3310 RAmS 3320 REM INIT.VALUE HEX 88 3340 LET RANOEotH207 'OUTPUT CHANNEL 0207 "RANGE SWITCH" 3360 LET X10.5-S 3380 LET RANGED(S)-S 3400 LET XIO.6m9 3420 LET RANGED(6)-9 440 LET XIO.7-4 346 LET RANED(7)04 A4 A4 4 3490 3500 3520 3540 3560 3580 3800 3620 3620 x 10. x1to. 9=2 RANOED(9)-2 X10. 10-3 RANGED( 10)-3 X10. 11=0 RANGED( 11 )-0 RANOEOC 11 )C) 3620 3640 3660 3680 3700 3720 3740 3760 3780 3800 3820 3822 3840 3860 3880 3900 3920 3960 3980 4000 4020 4040 4060 4065 LET RANCED( 11) =0 LET X10.12=1 LET RANGED(12)-l LET REM INIT.VALUE LET DAC12LSB-&H2001 12 BIT DAC LSB LET DAC12MSB-&H2011 12 BIT DAC MSB LET DAC16LSB-&H2021 16 BIT rIAC LSB LET DAC16MSB-&H2031 16 BIT DAC MSB OUT RANGE, RANGED(R) CHECKO0 AFLAG-0 OUT OAC12LSB,0 OUT DAC12MSB,0 OUT DAC16LSB,0 OUT DAC16MSB,0 LET IREAD-&H205' READ CHANNEL PICOAMMETER LET MISC-&H208l READ CHANNEL MISC. FUNCTIONS

RETURN

REM SUBROUTINE TO PLOT A ORAPH

REM

REM

ARANOE-AYALUE(E, 2)-AVALUE(E, 0) HEX 0 0 t

C

C C 4070 4075 4080 4100 4110 4120 4140 4160 5000 S 5020 #q 5040 5060 5080 3 100 5101 5102 5103 5120 CcC 5140 S5150 S5160 C. I 5180 5200 5210 'IF ARANGE<0 THEN ARANGE-0 AVALUE(E, 1)=ARANCE STARTuARANGE*TOP(RA-1 )*240'LPRINT Ell "START" TEPE (600/ (AEND-ASTART) IF START>,240 THEN START-24OILINE(K-(TEP*.1,,Y1)-(K+(TEP*.1),V-6),2,BF LINE(K-(TEP .1),(Y2)-START)-(K+(TEP .1),Y2-2),6,BF K-K4TEP*

RETURN

REM DIM MARKER YI1.286 Y2-299 N=X 1-301uMARK-ASTART LINE (N,YI4'8)-(N,Y2),7,B LINE (N,Yl)-(N-5,YI+8),7 LINE LINE (N-5,YI+8)-(N4.5,Y1+S),7:PAINT (N,Y1+2),2,7 PUT LOCATE 1,77ICOLOR 0,4,0,16zPRINT

N-XI

PUT (N-5,YI),LI7.,XOR COLOR 6,0,0,I61KEY OFF:LOCATE 14,73,0,12:PRINT MARK; LOCATE 15,731PRINT 1N

I

5200 COLOR 6,0,0,16:KEV OFFILOCATE 14,73,0,12:PRINT MARK; 5210 LOCATE 15,73SPRINT USINOS#.SS^"^"""AVALUE(MARK,)-AVALJE(MARK,0) 5211 COLOR 7,0,0,0 5220 ASuINKEYSIIF A*<Y"THEN 5220 5225 LOCATE 1,42UPRINT TIME$:A,-INKEYSIIF THEN 5225 ELSE IF LEN(As)>l THEN A$-RIOHTS(A*, 1) 5238 REM 5239 REM 5240 IF ASC (AS -72 THEN RA-RA+ 1: GOSUB 190~00:0'0TO 5020 5250 IF ASC(A*)-80 THEN RAmRA-ISOOSUB 19C00:00O 5020 5260 IF ASCAS)-77 THEN 5320 5280 IF ASC(A)-75 THEN 5420 5300 IF ASC(A)-13 THEN PUT (N,Y1),LI%,X0R:G0T0 5520 5310 OOTO 5220 5320 PUT 5340 N-N+TEPI MARK-MARK+ 1 5360 IF N>X2 THEN NmX2 5370 IF MARK)AEND THEN MARK=AEND 5380 PUT 5400 OOTO 5200 5420 PUT 5440 NnN-TEPI MARK-MARK-I 5460 IF N<Xl THEN NwXl 5470 ILIST 2RUN 3LOAD" 4SAVE" 5FILES 6C0NT 7,"LPTI SLOCATE 9COLOR 5480 5500 5520 6000 6020 6040 6040 6080 6100 6120 6140 8160 6180 6200 6220 6240 6280 6280 4300 6320 4340 6340 -6390 6400 1I ST PUT OOTO 5200

RETURN

REM *******SUBROUTINE TO CALCULATE DAC VALLIE-AMU***** AS-100 96455350 CS-. 033333330 AMUSn. 0333333* RESULTS.E*AMUS/ DS 9S-HEX RESULT#) 9.16 LSB9=RIOHTS (95,2) FOR ta1 TO L AwASC(MIDS(LSB$, 1,1)) IF A 64 THEN A-A-55100T0 6300 A-A-48 NEXT I RES-ADS (RESULTS) REAuCINT( (RES-D)/256) OUT &H202,D 2RUN 3LOAD" 4SAVE" 5FILES 6CONT 7,"LPTI 8LOCATE 9COLOR 4380 OUT &H202,D 8400 OUT &H203,REA 4420 RETURN 7500 REM ro READ 7505 REM' RSI1OUT RANGE,RANGED(R) 7510 OUT FUNC,CONSOLE+FIL.TP PRESSUIRE 7515 7516 7517 7518 7520 7521 7522 7530 7540 7550 7560 7571 7572 7573 7580 7585 7590 7590 IL IS RuIl:OUT JRANGE, RANGED(R): FOR 0=1 TO 24):NEXT Q, COLOR LOCATE 1,324PRINT"TIME-- LOCATE 1,423PRINT TIME$ GOSUD 2000

TPRESS-VALUE

RPRESSmR COLOR LOCATE 2,32:PRN-PES Xl-)- LOCATE 2,421PRINT USING'*.##*;VALUE; LOCATE 2.5OUPRINT R-4

REM

REM

R-7 OUT RANGE. RANGED(R)

RETURN

RETURN

T 2RUN 3LOAD" 4SAVE" 5FILES 6CONT 7, "LPT1 SLOCATE l;'CC'LOR 7700 7720 7740 8020 8040 8060 8080 8100 8120 8140 8160 C' 8180 8200 9220 8240 fj 8260 8280 8300 8320 8340 8350 8360 'S 940 I~r LIST OUT DAC16MSB,0 OUT DAC16LSB,0

RETURN

REM SUBROUTINE TO CREATE A FILE NAME IN THE CROSS REFERENCE REM TABLE FILE OPEN FIELD #1,8 AS OK$,4 AS TP$,4 AS SS$,4 AS SE$,10 AS DE$,S AS TE$ GET #1,1 ***ALLOCATE FIELDS IN ElUFFER*******

COUN-CVI(OKS)

IF COUN<=O THEN PRINT "NO FILE AVAILrABLE':GOTO 8360 KI-COUN+1 LSET OK$-MKI$(KI) PUT #1,1 LSET OK$SAMES LSET DE*UDATES LSET TES-TIMES LSET TPO-MKSS(TPRESS) LSET SS*-MKSS(ASTART) LSET SES-MKSSkAEND) PUT 01,K1 CLOSE #1

RETURN

***MOVE DATA INTO THE RECORD BUFFER** -4 2RUN 3LOAD" 4SAVE" 5PILES 6CONT 7, LPTI eLO(CATE 9COLC'R 1OPALET

I.

8400 OPEN -lR-,#1,LOOKUP.TABl-,40 '***SUBROUTINE TO SHOW THEC DIRECTORV***** 8420 FIELD *1,8 AS OK$,4 AS TPS,4 AS SS$,4 AS SES,1O AS DE$,S AS TES 8421 GET *1,1 8422 COUN=CVI(OKS)ICLS 8423 ASTART-CVI(SSS) 8424 AEND-CVI (SES) 8430 PRINT 111TB6"O NAME"TAB(20)'RNO"TAB(25)STARTTAB(32)"ENITA4(40)rIAT "TAB(51)"TIME"' PRINT 8440 FOR K1-2 TO COUN 8460 PRINT UIG##;K 8462 PRINT c 8463 PRINT "allo 8464 PRINT TAD(7)1 8465 PRINT OK~u 8466 PRINT TAD(20)1 8467 PRINT USINO'*"##;CVS(TPS)l 8468 PRINT TAD(25)1 8469 PRINT USINO"0**"jCVS(SS$); 8470 PRINT TAB(31)1 8471 PRINT USING"#**"jCVS(SES) 1 8472 PRINT TAD(37); 8473 PRINT OE~j 8474 PRINT T ILIST 2RUN 3LOAD" 4SAVE" 5FILES 6CONT 7, "LPTI SLOCATE 9COLOR IOFALET A7

'C

'C

I

8474 PRINT TAB(48) 1 8475 PRINT TES 8500 NEXT 1<1 8520 REM CLOSE #1 8540 RETURN 8600 OPEN **.SUBROUTINE TOi STORE THE CONTENTS OF AVALUE(X,2) 8635 FIELD #2,14 AS AMUNS ON DISK. ENTER WITH ASTART AND AEND INITIALIZED 8640 FOR CL-ASTART TO AEND ***FILE NAME IN AME$ 9660 LSET AMUN$-MKS$CAVALUE(CL,2)) 8680 PUT #2,CL 8700 NEXT CL 8720 CLOSE *2 8740 RETURN 8800 REM TO READ THE NAME OF DATA FILE 8801 REM OUT OF THE CROSS REFERENCE FILE CALLED 8802 REM LOOKUP.TAB, IDENTIFIED BY NRME,REMOVE 8803 REM ASTART,AEND DATA, AND XFER THE DATA TO THE 9804 REM ARRAY AVALLE(X,2) 8805 REM 8807 GET *1,NRME 8808 AMES-OKS 8810 ASTART-CYS(CSS$) 8812 AEND=CYS(CSES) 8812 AEND-CVS(SE$) ILIST 2RUN 3LC'AD" 4SAVE" 5FILES 6CONT 7,11LPT1 SLOCATE 9COLOR a. 9 9 *9 a 9. 9 9 9 9* a .9 *9 .4

#(I

4 re

C

8810 8812 8819 8820 8823 8840 8860 8880 8900 8920 ,9921 8922 8924 8925 8926 8927 8928 8940 9000 9001 9002 9003 9004 9004

ILIST

ASTART-CVS(CSS$)

AEND-CVS C ES) OPEN R-,#2,AME$,14 FIELD *2,14 AS AMUNS CLOSE #1 FOR CL-ASTART TO AEND GET #2,CL AVALUE(CL, 2)-CVS(AMUN$) NEXT CL CLOSE *2 OPEN R-,#2,"BKORNDl,14 SUBROUTINE T( FIELD *2,14 AS AMUNS STORED IN "BI FOR CL-I TO 300 **THE ARRAY AV GET 02,CL AVALUE(CL, 0)-CVS(AMUN$):AVALLIE(CL, 3)=CL NEXT CL CLOSE *2

RETURN.

CLSILOCATE 10,40,0:PRINTACKNOWLEDOE WITH

ASS-INKEYS

IF LEN(ASS)-O THEN 9001 IF ASC(AS$)-78 THEN RETURN IF ASC(ASS)-89 THEN 9019 IF ASCCASS)-89 THEN 9019 *2RUN 3LOAD" 4SAVE" 5FILES 6CONT 0 READ THE BAL.KOROLIND DATA KGRND" FILE AND PLACE IT IN ;LUE(X 2) Yes OR No" 7,"LPTI SLOCATE 5'COLOR 1 OPALET Li 9=I F NXIM.70 TMO FETt ON4 WI AX(MS)4N TM 9019 9" eMIm ILlP.,0 9M@ FIU. #1,14 0S p,4 AS TN,4 AS 550,4 AS 50,10 AS D1,8 AS TEI OW4 INIT02 MO0 LET OICMIS(INITI A8 ii 9100 CLOSE 9120 REUR 10000 LS ""'444 SUBRFWINE TO INPUIT THE NAME OF A FILE TO BE SAVED 10005 IRVJ ;(WAE 1

AMES

i0ol0 00513 9000, 1002000O38MOO 100M REUR 10200 RE NESNLOOKPTAB 't44 SUMJINE TO CALL (HIM DIRECTORY) ND THEN 102100OW913400 '44. ITFI HE NAME OF FILE TO BE USED BY (VIEWd 10215 LOCATE 23,5 'e SPECTRUM)I 1022 IWUK'SPECTRUM OSIREDIM 10230 00I9600 H 1 GE OT THE STARTING VALUES (ASTART,AND,ETC) 102400091320000 10245 EFLO1 20250 REUR 11000 aLs'LOCAIE 1,77:C ILIST 3M &OAD" 4SAYE FILES 6CONT 7,-LPTl 8OCATE 9CMOR IQpALET 10250 RETUR 11000 O.SoLOCATE 1,771COLOR O,2,0,0:PRINTIMIT- 11020 COO 4,0,0,0 11040 LOCATE 1,IIPRINTSTT- AMU-1 11042 LOCATE 2,IIIPRINT-IDTN-- 11044 LOCATE 3,119PINTFIAGE 1110- AMP- 11060 LOCATE 1,32PRN T E- 0 11060 LOCATE 2,321PRINTPRESSR- 11100 LOCATE 3,32:PINTAIN- 11120 LOCATE 1,55:PImT*D TE- 11140 LOCATE 2,55IPIN-EATOR-- 11160 LOCATE 3,551PRINY'IENTITy-- 11165 IF FLAMluI THEN 11525 11160 LOCATE 1,22,1,0,12 GE4 OT START SCAN 11200 605W 12500 11230 ASTMW&af(REsKMEsI 112 IF ASTART( OR A67MDT299 THU mo18 11240 LOCATE 2,22,11OOSUB 12500 1 H4 OT WIDTH (START+ITlaM SCAN) 11260 WMEW~( 1AENEQASTAT WIDE 11265 IF AWS( Ol A=W300 THN 12240 11270 IF ASTRT)EN 1)0 11180 21280 LOCATE 3,22,11OOSUW 22500 GE OT RANGE 11440 RAX~IEom2RMA 11440 RWA SFES) RA ILIS? =M ZOA 4SA',E" FILES 6CONT 7,'LPTI SLOCATE 9COLoR 1OFp.E

L

11460 LOCATE 2,65,1:000132500 EOEATOR 21468 IF LEN(SP 0>l14 THEN 1140 11460 OPERI.BESPNES, 1150 LOCATE 3,63, 11 OOSUB 1250 iOT IDETITY 11505 IF LBI(RESPNSE$S)6 THEN 12500 11320 1152a LOCATE 1,42,01PRINT TIMES 11526 LOCATE 1,22,0FINT ASTM~T 1152 LOCATE 2,22,0PINT AEN-ATAT 1152 LOCATE 2,42,01PA1Nt USING% ##'TPESSI LOCATE 2,50, 2:PRINT RPRESSI 11330 LOCATE 1,65,OIPRINT DATE$ 21535 LOCATE 3,42,01PINT GAIN 115000G 3 15000 00 WRITE THE SRE 22560 ER 00137500' READ THE TOTAL PRESSURE 11560 OWT FUNC,CONSOLEFIL+MU.T 1220 RawIN 11640' 12660 1160' 11700 12720' 1174Q' 12760' 1270 ILlST 3M IWOf 4SAVEO FILES 6CUNT 7,'LPTI BLOCATE 9aOR IOPALET 12230 11800 A9 -'4 110 11860 11920 11940 11960 12000 REM 12020 PE 12040 REM 12060 REM 12100 RE 12120 REM 12140 REM 12160 REM 12240 REM 12500 RESFONS~f '#4**H4SURWINE TO INPUT VALUES n4~ 12510 AlImINW11hIF LEN(AS)N0 THEN 1240 12WO PRINT A 1 ILIST "M &M*A 4SAYE' SILES 6CONT 7,-LPTI SLOCATE 9COLOR IOPA.ET 1230 PRINT All 125 iF A9()mI3 THEN RETURN 1255 00710 12510 '4.44H.~hmn4*.4..*H 12560 REM 100 REM mHOROTINE FOR TEAR PRINTOUT OF SPECTRUM.n.~i 1A 3DOS OS:RlI~:LEa&:T:0T292:Az06 t 13007 LOCATE 1,77:COLO 0,2,0,B0:PRINT 'WAIT* 13006 COO 6,0,0,0 13010 LINE (RI,80(-(LEW,90),1 'TOP LINE 13020 LINE (RI,IOO)-(LF,8.A,I,V '2N THICK LINE 13030 LINE (RI, 124(-(LU, 1241 130 13040 LINE IRI, 10)-(LFf, 148),l '4TH 13050 LINE IRI,I72l-(LEF,172),l 13060 LINE (RI, 19)-1LEF, 961,1 16Th 13070 LINE (RI,22O)-(LE,22O,1 '7TH 13060 LINE (RI,244)-(LEF,244(,I '81)H 13090 LINE (RI,2&8)-(LEF,268),1 19TH 13100 LINE 1 13110 LINE (I4O,1.A-(140,9OTI,I 13120 LINE (LU, TOP)- (LE5, BT),1I 'LEFTNO 23130 LINE (RI,TOl-(RI,8WT(,1 'RI34TMOST 13140 LINE (254, IA)-(24, DT), 1 13180 LINE (37 ILIS? WM &2.O 4SAVE- WILES &CONT 7,LPTI 8LOCATE 9CU.LO 1OPXVE 13150 LINE (370,BLA)-(370,OT),1 13160 LOCATE 8,11:PRINTI"MASS' 13170 LOCATE 8,171PRINTIIINTENSITYVl.

13180 LOCATE 8,3O3PRINT"CALCULATEDI- 13190 LOCATE 8,44sPRINT"DBACKOROUNDII 1 13200 IF EFLAO THEN LOCATE 24,6OZPRINT "NO' DATA AVAILABLE".,*FOR DEL=1 TO 2000 NEXT DELIOOTO 13570 13210 13220 13230- 13240 NI1-ASTART 13250 S=O SORT 13260- 13270 FOR ImNl TO AEND 13280 IF AVALUE(I,2) AYALUECI+1,2) OR 1=285 THEN 13330 13290 Z.AVALULE(I,2):X-AVALULE(I,3) 13300 AVALUECI,2)-AVALUE(1+1,2)IAVALUE(1,3)-AVALUE(I+1,3) 13310 AVALUE(1.1,2)-Z:AVALUE(1,1,31-X 13320 Sol 13330 NEXT 1 13340 IF Sol THEN 13250 SORT 13341 13342 13342- ILIST 2RUN 3LC'AD" 4SAVE11 5FILES 6COiNT 7, "LPTI 8LOCATE 9COLOR i1iPALET 13343 13344 13350 13360 13370 13380 13390 13395 13400 13405 t3410 1-41'0 13430 13440 13450 13460 13470 1 34W0 13490 13500 13510 13520 13530 1353 1LIST AB-ANDI AC-AEND-6 FOR ImASTART TO AENE' TEMP2.TEMP2+AVALUE (1,1) NEXT I MAXPK-AVALUE (AB, 2) FOR I=AD TO AC STEP-I 'IF AVALUE(I,1)0 THEN X(I)=IE-13II3O 13420 X(l)-(AVALUE( I,2)/MAXPK)*100 NEXT I *AB=ASTARTIAC=ASTART+7 FOR IxvAEND'1 TO AEND-6 STEP-1 LOCATE 10+INC,11IPRINT AVALUE(I,3);'MASS LOCATE 10.INC,I7:PRINT UJSING4 "#.##*^'-";AVALUE(I,2);1INTENSITY LOCATE 10+INC,3OIPRINT USING "###.##/";ABS(X(l));,'CALCULATEDI LOCATE 1O+INC,44:PRINT USING 'BACK1OROUND INC INC+2 NEXT I 2RUN 3LOAD" 4SAVE" 5FILES 6CCINT 7, "LF'T1 SLOCATE 9COLOR 1(OPALET to t 13530 of 13535 4 13536 4 13540 13542 4 9 13550 v 13560 13570 f t 14000 I 1401 r I I 14020 14030 14040 14050 14060 14070 4 14080 14090 *1410 14110 14120 14130 14140 14140 1I ST 14140 q t 14150 14160 14170 14172 14173 14175 14180 14190 14200 14210 14220 14230 14240 14250 14260 NEXT I LOCATE 1,771COLOR 0,4,0,16:PRINT COLOR 6,0,0,0 AS-INKEYSSIF THEN 13540 AS-INKEYS:IF THEN 13542 ELSE IF LEN(AS)>I THEN A$=RIG3HT$CA$,1) IF ASC(A$)=13 THEN 13570 COTO 13540

RETURN

REM SCAN SUBROUTINE*********** CLSICOLOR 6,0,0,0: IND=1:AFLAO=o LOCATE 1,671PRINT"-TIME SCAN" FOR 1w4 TO 10 STEP 2 LOCATE 1,67tPRINTIIPEAKIII/2-1 1 :COLOR 7,0,o,16:LOCATE I,74:PRINT" KEY OFF LOCATE 1,74 GOSUB 12500 PKSEL( IND, 0)-VAL (RESPONSES) IF PKSEL(IND,0))285 THEN 14080 IF PKSEL(IND,0)<l THEN PKSEL(IND,C0)=0) INDmIND+1 COLOR 6,0,0,0 COLOR 6,0,0,0 2RUN 3LOAD" 4SAVE" 5FILES 6CONT 7, "LPTI SLOCATE ;'C'LC'R 1 OPALET

I

*1 COLOR 6,0,0,0 NEXT I LOCATE 16,67:PRINT"PERIOD" LOCATE 17, 67tPRINT".-... SECONDS": LOCATE 17,67: OOSIB 12500 IF VAL(RESPONSES)-0 THEN PER-60:0OTO 14175 PER-VAL (RESPONSES) LOCATE 17,67IPRINT PER" SECONDS" IF PER<10 OR PER>900 THEN 14160 'MIN. 12 SECS LOCATE 12,67:PRINT"-TOTAL TIME LOCATE 13,671PRINT PER*540/6011 MINUTES" LOCATE 14.67sPRINT USING "#*.##":PER*54O/60/60:LOCATE 14,73:PRINT" HOURS' TOP-61LEFTmr41 OTw2461RI0HT-581 'LINE(LEFT, TOP)-(LEFT, DOT), 2 'LINE(LEFT,DOT)-(RIGHT,DOT) ,2 FOR AG-mTOP TO DOT STEP 24 LINE (LEFT-5,AQ)-(RIOHT,AQ),2 All 1 14270 14280 14290 14300 14310 14320 14330 NEXT AQ INC-93ZAHL-0:KEY OFF FOR A-LEFT TO RIGHT STEP INC LINE (A,BOT+5)-(ATOP),2 NXTuA/9ULOCATE 23,67IPRINT"M I N U T E S" LOCATE 22,NXT:PRINT MIDS(STRS(ZAHL),2,1); REM IF ZAHL<-9 THEN 14390 ILIST 2RUN 3LOAD" 4SAVE" 5FILES 6CONT 7, LPT1 8LOCATE 9COLCIR 14330 14340 14350 14360 14370 14380 14390 14400 14410 14420 14430 14440 14460 14470 14480 14489 14490 14500 14510 14520 14525 14527 14530 REM IF ZAHL(mO THEN 14390 LOCATE 23,NXT:PRINT MID$(STRS(ZAHL),3,I); REM IF ZAHLC-99 TH4EN 14390 LOCATE 24,NXT:PRINT MIDS(STRS(ZAHL),4,1); REM IF ZAHL<-999 THEN 14390 LOCATE 25,NXT:PRINT MID$(STR$(ZAHL),5,1); ZAHLaZAHL+PER*9/60 NEXT A

REM

FOR EW-1 TO 21 STEP 2 READ ZAHL LOCATE EW,2:PRINT USING "**';ZAHL NEXT EW DATA 10,9,8,7,6,5, ,3,2,1,0

RESTORE

OH-OI RA-ii FOR PLOTT-LEFT TO RIGHT FOR IND-1 TO 4 E-PKSEL(IND,O):IF E-O THEN 14560 GOSUB 6000 IF AFLA-i1 THEN R-PKSEL(IND+4,1U GOSUB 2000 tr tr.

I -e

I*

1 ILIST 2RUN 3LOAD" 4SAVE" 5FILES 6CONT 7,LPT1 SLOCATE 9COLOR

I

I

I

14527 14530 14540 14, 14545 14550 14560 14565 14570 14572 14575 14580 14590 14600 14610 14612 14615 14620 14630 14640 14650 14651 14652 14653 IF AFLAG-i THEN R-PKSEL(IND+4,1) OOSUD 2000 IF AFLAO 0 THEN PKSEL(IND+4,1)-R PKSEL(IND,1)-VALLE*10 -R NEXT IND COL-4 FOR INDa1 TO 4 IF PKSEL(IND,O)-O THEN 14610 RUmPKSEL(IND+4,1)-i PINT-PKSEL(IND,I)*TOP(RU)*240 PSET(PLOTT,DOT-PINT),COL-3 COL-COL.2 NEXT IND

AFLAG-I

OHmOH+1 OOSUD 14960 ASAVEwTIMER GOSUD 14960 IF TIMERASAVE+PER THEN 14640

AS-INKEY$

IF LEN(AS)-0 THEN 14660 IF ASC(A$)-13 THEN 14665 lii ILIST 2RUN 3LOAD' 4SAVE" ZPILES 6CONT 7,'LPT1 SLOCATE 9COLOR 1OPALET 14653 14660 14665 14670 14690 14690 14700 14720 14730 14740 IF ASC(AS)-13 THEN 14665 NEXT PLOTT

IND-!

FOR In 5 TO 11 STEP 2 LOCATE I,67sPRINT'9.99*1^-'PKSEL(IND, IND.IND+1 NEXT I FOR DEL-I TO

BEEP

NEXT DEL a

L

~t >4 r i :r -1~W 14760 14770 14780 4790 14805 14e10 14820 14830 14840 14850 14860 14870

A$,INKEY$

IF LEN(A$)0O THEN 14760 IF ASC(AS)<)13 THEN 14760

RETURN

ILIST 2RUN 3LOAD" 4SAVE" 5FILES 6CONT 7,"LPTI SLOCATE 9COLOR IOPALET 14860 14870 14880 14890 14900 14910 14920 14930 14940 14950 14960 14970 14980 14990 14995 15000 15020 15040 15060 15080 15100 15120 15140 15140 1LIST REM SUBROUTINE TO RETURN THE PRESENT TIME IN SECONDS TIMER-VALRIGHTS(TIMES,2) ):LOC:ATE 25,1 TIMERTIMER+(VAL(MID(TIME$,4,2))*60) TIMER-TIMER.(VAL(LEFTS(TIMES,2))*36QQ)

RETURN

REM SUBROUTINE TO CREATE A SCALED GRAPH REM CLS

FULL-AEND-ASTART

FEIN-600/FULL GROB-MEDIUM*4 COLOR 7,0,0,0

PALETTE

PALETTE

2RUN 3LOAD' 4SAVE" SFILES 6CONT 7. "LFTI SLOCATE 9COLOR lOPAPL 4'

WI(

Si It

ET

15140 15160 15180 15200 i 15220 15240 15260 15261 15262 *eWQ 15263 C 15264 15265 15266 15267 15268 A4a4 15269 15270 15271 15272 15280 15300 15320 15340

PALETTE

X1- 411Y1-42:X2-641IY2-282 COLOR 2,0,0,0 REM LINE (X1,Y1)-(X2,Y1 'TOP LINE FOR D-Y1 TO Y2 STEP 24 LINE(XI,D)-(X2,D) 'MITTLE LINES NEXT 0 COLOR LOCATE 4,2iPRINT"10" 1 LOCATE 6,31PRINT"91; LOCATE 8,31PRINT'8"; LOCATE 10,31PRINT"7"I LOCATE 12,33PRINT1'61 LOCATE 14,3iPRINT"511; LOCATE 16,33PRINT"41; LOCATE 18,3PRINT-3-; LOCATE 20,3PRINT"2" LOCATE 22,32PRINT'' 1 LOCATE 24,3IPRINT10"; COLOR 7,0,0,0 FOR W-XI TO X2 STEP OROB LINE(W,Y2+2)-(W,Y2+15) NEXT W 'ILIST 2RUN 3LOAD" 4SAVE' SFILES 6CONT 7, "LPTI SLOCATE -PCOLOR

IOPALET

15360 15380 15400 15420 FOR WaXI TO X2 STEP MEDIUM

LINE(W

4 Y2+2)-(W,Y2+8) XT W IF FEIN 3 THEN COTO 15500 A13

L,

C

15440 15460 15480 15500 15620 19000 19001 19002 19003 19004 19005 19006 19007 19008 19010 19020 19040 19060 19080 19100

ILIST

19080 19100 20000 20010 20015 20020 20021 20022 20023 20024 20040 20060 20080 20090 20100 22000 22001 22002 22003 22010 22020 24000 24001 24001

ILIST

FOR W=X1 TO X2 STEP FEIN LINE(W,Y2+2)-(W,Y2+4) NEXT W

REM

RETURN

IF AEND-ASTART-O THEN LOCATE 12,40,O:PRINT"NO DATA AVAILABLE,!cOTO 22020 IF RA>12 THEN RA=12 IF RA<5 THEN CLSIFLAGI-IZOSUB 11000 FLAG 1- LOCATE 3,22:PRINT RA LOCATE 3,65:FRINT AMES LOCATE 2,22:PRINT AEND LOCATE 2,65:PRINT OFER$ GOSUB 15000 K=41 FOR E-ASTART TO AEND GOSUB 4000 NEXT E 2RUN 3LOAD" 4SAVE" 5FILES 6CONT 7, "LFT1 8LOCATE 9COLOR IOFALET NEXT E

RETURN

IF AEND-ASTART=0 THEN LOCATE 12,40,0:PRINT"NO DATA AVAILABLE1:0OTO 22020

REM

FLAGl-IGOSUB 11000 K-41:FLAO1-0 IF FLAGBO=1 THEN 20022 ELSE 20040 FOR EI-ASTART TO AEND AVALUE(EI,0)=O NEXT El FOR E-ASTART TO AEND GOSUB 4000 NEXT E LOCATE 3,22:PRINT RA COLOR 4:LOCATE 1,42:PRINT TIMES REM GOSUB 7500 DISPLAY TOTAL PRESSURE REM A$-INKEY$ REM IF LEN(A$)=0 THEN 20100 REM IF ASC(A$)<>13 THEN 20100 GOSUB 5000

RETURN

REM SUBROUTINE TO CALIBRATE CLSICOLOR 6,0,0,16:LOCATE 10,38 CLS'COLOR 6,O,0,163LOCATE 10,38 2RUN. 3LOAD" 4SAVE" 5FILES 6CONT 7,LPTI SLOCATE 9COLOR 1OPALET Ir 4 1.(

I

I

II

4 4

*I

24000 REM SUBROUTINE TO CALIBRATE 24001 CLSICOLOR 6,0,O,16:LOCATE 10,38 24002 PRINT "Calibrating On* Moment Please" 24010 24040 E-28 24045 GOSUB 6000 24050 OUT RANGE,RANGED(R) 24055 OUT FUNC,CONSOLE+FIL+FAR:FOR Aw1 TO 3000:NEXT A 24060 GOSUB 2000 24061 IF YALUE.8 THEN RUR+I:IF R-12 AND VALUE<.S THEN 20470:IF OTO 24050 24062 IF VALUE>9. THEN R=R-1:IF R-5 THEN R-6:GCTO 24050 24063 IF VALUE-0 THEN R-R-1:GOTO 24050 24070 VALY-R 24080 FARVAL-VALUESLOCATE 11,40,01PRINT"'FARVAL="FARVAL"X10-"R 24095 Rw7 24090 OUT RANOE,RANGED(R) 24100 OUT FUNC,CONSOLE+FIL+MULT:FOR AwI TO 2000:NEXT A 24120 GOSUD 2000 24121 IF VALUE.8 THEN IF R-12 THEN 24130 ELSE R-R+lIGOT 24090 24122 IF VALUE>9.5 THEN R-R-1:OTO 24090 24123 IF VALUEO THEN RuR-1:GOTO 24090 24130 VALX-R 24140 MU THEN R=12:G A14

I

4 11 ILIST 2RUN 3LOAD 4SAVE" 5FILES CONT 7, LPTI SLOCATE 9COLOR 1OPALET 24130 24140 14160 24180 24200 24220 24230 24240 24250 24260 24265 24270 24280 24290 24300 24303 24304 24305 24306 24307 24308 24309 24310 24311

ILIST

24310 24311 24312 24320 24370 24380 24390 24400 24410 24420 24430 24440 24450 24460 26000 26010 26020 26030 26040 26045 26050 40000 40001 40002

ILIST

VALX=R

MULTVAL=VALUE'.LOCATE 12,40,0:PRINT MLILTVAL= MUILTVAL'XIO- R LOCATE 13,40,0) GAIN-(MULTVAL*(10^(-VALX)))/(FARVYAL*(1:0)'(-VALY))):PRINT"GFAIN="GAIN REM FOR A-1 TO 300 LOCATE 14,38 PRINT"Redirg Background Orie Morent Please" CHECK=1 FOR E=ASTART TO AEND GOSUB 6000 GOSUB 2000 NEXT E AME$. "BKGRND" OPEN "LOOKUP. FIELD #1,8 AS OK$,4 AS TPS,4 AS SSS,4 AS SE$,10 AS DES,S AS TE$ LSET 01<5AME$ LSET DES=DATE$ LSET TE$sTIME$ LSET TPS"MKSS(R) LSET SS$=MKSS(ASTART) LSET SE$=MKS,.( AEND)

PUT

2RLN 3LOAD" 4SAVE" 5FILES 6CONT 7, 1LPT1 8LOCATE 9COL0R IOPALET LSET SE$=MKS$(AEND) PUT #1,2 CLOSE #1 GOSUB 8600

RETURN

OPEN BK0iNDW, 14 'SUbROUTINE TO READ BG FROM FIELD #2,14 AS AMUN$ CLOSE #1 FOR CL-ASTART TO AEND GET #2,CL AVALUE(CL,2)=CVS(AMUN$) NEXT CL CLOSE #2

RETURN

REM *******SUBROUTINE TO DISPLAY STORED BACKGROUND ASTART-25:FLAGBG 1 OOSUB 24390 OOSUB 20000 FLAGBG-0

RETURN

CLS

LOCATE 24,401PRINT'INPLIT 101 ZERO TO EXIT" 1 LOCATE 12,401INPUT;"AMU VALU 2RUN 3LOAD" 4SAVE" 5FILES 6CONT 7,"LPTI 8LOCATE 9COLOR lOPALET NEXT CL CLOSE *2

RETURN

REM *******SUBROUTINE TO DISPLAY STORED BACKGROUND ASTART-251FLAGBG1l AEND9O OSUB 24390 GOSUB 20000 FLAGBO-0

RETURN

CLS

LOCATr 24,4OIPRINTINPUT 0' ZERO TO EXITI LOCATE 12,408INPUT' "IA VALUE";E IF E=O THEN 40030 GOSUB 6000 GOTO 40001 0OSUB 6000

RETURN

~jI 24440 24450 24460 26000 26010 26020 26030 26040 26045 26050 40000 40001 40002 40005 4001 C 40020 40030 40040

AIS

yi '40100 REM ROUTINE TO PLACE INSTROMENT IN REQUIRED MODE !40110 CLS 40120 LOCATE 2,14:PRINT "STANDBY--FILAMENT ON, MULTIPLIER ON"52 40130 LOCATE 3, 14:PRINT "OFF FILAMENT OFF, MULTIPLIER OFF-52 Ok 00000000 ILIST 2RLUN 3LOAr'' 4SVE" 5FILES 6CO:NT 7, 'ILFTI 8LfOCATE 'KOL OR IOPALET r t

Claims (11)

1. A system for the analytical determination of organic substances in low concentrations by transferring the substances from a source at a relatively high pressure into a mass analyzer at a low pressure, said system comprising: a metering device by which the source is selectively connectable to the mass analyzer for transferring the substances, o o a quadrupole mass spectrometer in said mass 0 0 aanalyzer, said quadrupole mass spectrometer having a high sensitivity electron multiplier, a vacuum pump for creating a source of vacuum to said quadrupole mass spectrometer, and a mass correction lens disposed between said quadrupole mass spectrometer and said vacuum pump for regulating by the area of its aperture the flow of said substances from said quadrupole mass spectrometer toward said vacuum pump, whereby said substances are detectable S with increased sensitivity by said quadrupole mass spectrometer.

2. The system as claimed in claim 1, further comprising an ion pump for obtaining said low pressure at said mass analyzer, and wherein said ion pump is connected at a right angle to the connetio between said quadrupole mass spectrometer and said vacuum pump. s

3. The system as claimed in claim 1, wherein said vacuum pump is a turbomolecular pump. 26 c weiu S spctroeter 7 So 9 0 58 8 5 o so 0r 4 0,1

4. The system as claimed in claim 1, wherein said quadrupole mass spectrometer also includes an ionizer for generating ions from said substances and a mass filter disposed about an axis between said ionizer and said electron multiplier for selecting a particular ion mass for transmission from said ionizer to said electron multiplier, and wherein said metering device admits said substances to said mass filter in a direction substantially perpendicular to said axis, and said vacuum pump is connected to said ionizer generally along said axis and draws said substances along said axis from said mass filter toward said ionizer. The system as claimed in claim 1, wherein the mass correction lens has an aperture area which is selected to optimize the detection of a particular molecular mass in said substances to be detected.

6. The system as claimed in claim 5, wherein the mass correction lens has an aperture having an area of about 50% of the area of the passage between the mass spectrometer and the vacuum pump.

7. The system as claimed in claim 6, wherein the passage between the mass spectrometer and the vacuum pump is provided by a pipe having an internal diameter of about 48mm.

8. A system for the analytical determination of organic substances in low concentrations by transferring the substances from a source at a relatively high pressure into the mass analyzer at a low pressure, said system comprising: 27 Itt 0 I ''i a metering device by which the source is selectively connectable to the mass analyzer for transferring the substances, a quadrupole mass spectrometer having a high sensitivity electron multiplier in said mass analyzer, a vacuum pump for creating a source of vacuum to said quadrupole mass spectrometer, and S(d) a mass correction lens disposed between said quadrupole mass spectrometer and said vacuum pump for regulating the flow of said substances from said auadrupole mass spectrometer o toward said vacuum pump, wherein said mass correction o .lens has an aperture having an area which is variably adjustable, whereby said substances are detectable with increased sensitivity by said quadrupole mass spectrometer. 9, The system as claimed in claim 8, further comprising a data processing unit and an automatic adjusting device for adjusting the area of said aperture in response to data transmitted by said data processing unit to said automatic adjusting device. 4It 4 The system as claimed in claim 9, wherein said data processing device includes means for commanding said quadrupole mass spectrometer to i analyze the concentrations of a number of different substances in said sample, and wherein said data processing device is programmed to command said quadrupole mass spectrometer to analyze the concentrations of said substances and is also programmed to adjust the area of said aperture to a different optimum area for the detection of each of said substances. 28

11. The system as claimed in claim 10, wherein the optimum area for each substance is prestored in memory in said data processor.

12. The system as claimed in claim 10, further comprising an automatic device for adjusting an operating value of said electron multiplier in response to data transmitted by said data processing S• unit, and wherein said data processing unit is o programmed to adjust said operating value of said electron multiplier to respective different values for different ions from said substances. ft °13. The system as claimed in claim 12, wherein said operating value is the gain of said multiplier and said automatic device adjusts the value of high voltage applied to said electron multiplier to cause electron multiplication.

14. The system as claimed in claim 13, wherein said operating value is predetermined for the mass of each of said ions to optimize the signal-to-noise ratio of detection of the ions, and the predetermined operating values are stored in a memory of said data processing unit and later recalled for automatic adjustment during mass analysis. A method of using a quadrupole mass spectrometer for the analytic determination of organic substances in low concentrations by the steps of admitting a flow of said substances through a i metering device to said mass spectrometer while said spectrometer is being evacuated by a source of-high vacuum, the substances flowing through a mass

29- .E m correction lens placed in the flow between the mass spectrometer and the source of vacuum, and the mass correction lens having an aperture, the area of which is preselected to optimize the detection limit of a particular substance to be detected. 16. The method as claimed in claim 15, wherein said source of vacuum is a turbomolecular pump, and an ion pump is also used prior to analysis to obtain a high vacuum in said mass spectrometer. t 17. The method as claimed in claim 15, wherein the mass spectrometer has an ion source, an electron multiplier, and a mass filter placed along an axis between said ion source and said electron multiplier, and, wherein said sample is admitted to the mass filter and removed along said axis from said ionizer by said source of vacuum. 18. The method as claimed in claim 15, wherein the area of said aperture in said mass correction lens is variably adjustable, and wherein said method further comprises setting said area to a predetermined optimum for the substance to be detected prior to mass analysis for that substance. 19. The method as claimed in claim 18, further comprising the steps of adjusting an operating value. for said electron multiplier to different preselected values for the analysis of different fragment ions for said substance to be detected in order to optimize the signal-to-noise ratio of detection for different ion masses. DATED this 4th day of October, 1989 SCOULSTON INTERNATIONAL CORPORATION AND St 'GESELLSCHAFT FUR STRAHLEN-UND UMWELTFORSCHUNG mbH Attorney: PETER HEATHCOTE Fellow Institute of Patent Attorneys of Australia A. of SHELSTON WATERS 30 T' t)6