Firma:              Unicam

Modell:                         610

Kommentar:     Dokumente engl.

The AUTOMASS is a mass spectrometer of the new generation.

Compact, performing and evolutionist, this machine has been invented to liberate the owner of all classical obligations attached to using such an instrument.

All the sequences going from the starting-off until the printer ending results can be elf ected automatically, so allowing the owner to devote entirely to the analysis the needs to carry out.

The AUTOMASS benefits of up-to-datecomponents, joined to an optimized rod by simulation on computer. Its electronic is based on an architecture style multi-processor- that permits to run permantly all the parameters corrected to the instrument and instantly assures the data acquisition Liberated 01 this servitudes, the LUCY. program can also function in multi-taches- allowing an exploration of the data at the same time as a working acquisition.

This program can also run an analysis of the injection until the automatic printer of the analysis report.

Of an exceptional accessibilitythe AUTOMASS perrnits a sure utilization and an easy maintenance helped bv autodlagnostic functions in case of a break-down.

2 -ARCHITECTURE

2.1     Generalities

Composed of two seperate parts, the chassis trom top to bottom, the AUTOMASS, in a few minutes can be liberated of its (cover) dressings, allowing the direct access to the ditterent components.

The two principle functions, physical and electronic, are seperated entirely, the access at the inferior, in case of preventive intervention by pumping, tor example is largely made easier by the releasing of the upper chassis.

These solutions allow to reduce the time of the intervention on the AUTOMASS, assuring a stable and optimal function of this one.

      2.2     Lower chassis

In this part, are grouped all the physical functions of the machine (envelope, pumping, electrovalves, etc...) also the reputed functlons source drawer tor the electronics (molecular pumps alimentations, THT alimentation, and HF alimentation ot the quadrupole, etc...)

Joined to the box «HT»   the envelope assures the functions of maintenance to the pumping system, ot the center of the sub ensembles (source, quadrupole, detection) and the guiding of the source drawer during an interference on this one (cleaning tor example).

So as to insure a perfect stability this one is also thermostated.

The access to all these chassis tunctions (pumping, electrovalve, see even quadrupole) was studied to limit to a maximum the immobilization of the System during the daily interventions on emergency repairs.

2.3     Upper chassis

This chassis can be split-up in two parts

    - behind, for the power electronic,

- in front, for the command and control electonic.

This configuration allows to avoid all risks of noise or instabllity owing to the cohabitation of strong powers with a sensible electronic.

In the behing part of this chassis one can find a plug-in alimentation block and different cards, associated with functions, especially specific:

  - alimentation of the quadrupole rods (tilament, amplitier HF, heating resistances...)

      - alimentation and function commands ( ventilaters, electrovalves...),

      - alimentation of the electronic and pumping.

At the front of the chassis, the different functions necessary for the control of the parameters and to their commands am run by two microprocessors, and are assured by the specific cards (filament alimentation, engins, etc...)

The choice of associating a card to a function simplifies greatly the diagnostic, and generally limits the repairs by simple changing of the concerned card.

The accessability offered by such architecture joins to the autodiagnostic programmes allowing, in case of break-down,for the owner to operate himself the exchanging of the card, Iike this the cost of the intervention and the tirne of immobilization of the machine is little.

3-     PHYSICAL ARCHITECTURE (FIG 2.2)

3-1   Interface GC

Constant regulated temperature and of an ininerte internal material. TRhe interface permits, besides the direct transfer of the elf luent chromatographic the introduction in the source of the calibration product (PFTBA) and, tollowing the options, the reacting gas.

     3-2   Source and Inlet optics

Mounted on the «drawer source » the source and its inlet optics associated can be replaced without adjustment cnetering.

Of a new conception optimized by simulation on computer it permits to reach an impact Electronic (El). The excellent detection level, thanks to a heavy output (> 10-7Cb/G)by autorizing an easy functioning by a lower ionization energy .15eV.

The mounting can, by simple source block exchanging, and of optics block, become a system adapted to the chimical ionization. In this case, the AUTOMASS can generale the perfect spectres, as much as in positive ions as negativ ions.

     3-3   Quadrupole

Issue of quadrupole who made the reputation of the mass spectrometer «NERMAG» this one, AUTOMASS preserves an excellent transmission and a perfect resolution associated to the system «Resolve» and to the changing prefilters.

They present a life time «Infinie», but can eventually be replaced in a few minutes.

     3-4   Detection

Based on a conversion out axis of the ions to photons. The detection presents a perfect stability associated to an excellent dynamic.

The use of very high tensions (+ and -10kv) permits to detect very low signals and assures a perfect function whatever the polarity of the positive and negative ions. The passage from a mode to another being effected by commutation of low tensions (alternative detection +/-).

     3-5   Pumping and envelopes

By using the turbo-molecular of high capacity, associated to an optimized source for each mode (low gas debit reacting in CI) permitting to obtain a compact system, situated at the interior of the machine, ensured a start-up of the system in a few minutes. The maintenance of such a configuration is easy and cannot he carried out only once a year.

By it conception, the envelope is single tor all the models, giving Hie machine more evolution. It permits also, to obtain a perfect differential pumping by maintaing an high vacuum at the side of analyser.

4- ELECTRONIC ARCHITECTURE

4-1 Generalities

The electronique of the AUTOMASS is entirely wn by micro-processor. These ones communicating with the PC via an extension card of the Bus AT situated in this one.

The pilotage functions and the control of the machine are camed out by the u-controler .These functions are principally:

-   pumping and vacuum,

-   temperature and heating,

-   generation and control of the tensions and valves,

-   command and control of the electrovalves,

   command and control of the machine.

The functions joined to the acquisition parameter files are assured by the signal. These functions are principally:

-   mass range,

-   scan speed,

-   scan mode and algorythms of associated calculations

-   alimentation of photo-multiplier.

A zone called «correction» permits to give back the machine entirely linear and pertectly optimised whatever the mode of ions these adjustments react on realtime for optimised the tactor depending on the mass such as:

-   mass position (calibration),

-   resolution,

-   polarization,

-   resolver (2 parameters),

-   optical issue.

All these cumulated tunctions, the AUTOMASS comes forward facing the PC like a perfect machine, linear, optimized on each mass, memorizing the obtained spectra.

At the end of the scan, the PC is finally interupted to receive in block the memorized spectra.

The PC can be seen when liberated of all controls of the AUTOMASS during an analysis, which permits to work on «multi-taches« in an efficient manner.