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ASI are pleased to announce the introduction of their new Compact 'PTR600' PTR-MS System. Designed and Manufactured by Anglo Scientific Instruments this new advanced PTR-MS system is designed for trace level detection of Volatile organic compounds (VOC's).





Key Features

bulletChoice of reagent Gas
bulletHigh Sensitivity 
bullet (Sub ppb detection)
bulletCompact & Light Weight
bulletVery low Power requirements
bulletEasy maintenance.
bulletVery Low cost.


Front View of the New Production Instrument

PTRMS is a very sensitive instrument for the detection and measurement of trace levels of VOCís. It incorporates a soft ionisation process by producing H3O+ ions from a discharge ion source these are then combined with the sample gas that enters through a separate inlet. The charge from the H3O ions are transferred to the VOCís within the sample that have a higher proton affinity. Normal air gases N2, O2, Ar, CO2 etc have a lower proton affinity and do not become ionised. The VOCís after passing through a drift tube to remove cluster ions are then analysed and detected by the mass spectrometer

    Choice of reagent Gas. (Optional)

A wide choice of different reagent gases with different proton affinities can be selected to suit a wide range of different applications. Either a single reagent gas facility can be provided or a switchable (up to 5) to aid in identification of unknown trace VOC's.

A 45mL water container mounted on a temperature controlled panel is fitted as standard. It will provide approx 100 hours use before refilling is required. It is easily accessible by the user and can be topped up or refilled within a few seconds. 

 Additional Reagent gases, if required, are contained within small gas bottles built into the side or front of the system. They are fitted with 'quick fit' connectors that allow easy removal for replacement or recharging .


Compact & Light Weight.

This 'Table Top' PTR-MS system measures only 64cm x 36cm x 34cm and weighs from 32 Kgrms (Depending on options chosen) It is the only portable PTR-MS system available  that can be easily transported in the boot of a small car for field use, and can easily be carried between 2 people for 'On Site' analysis.

Very low Power requirements

The system consumes between 80 -90Watts (Depending on options). This is only 8% of the power requirements of competitive PTR-MS systems, and is the only PTR-MS that will also run on a small 24Volt rechargeable battery pack making it ideal for environmental applications in the field.



Ion Source:-
The new 'Plug In' discharge Source is easily removable for cleaning or replacement by the user.
The electronics unit automatically adjust the discharge voltage to maintain a constant discharge current irrespective of source pressure or temperature thereby providing a very stable reagent ion supply.
The discharge current can be manually set by the user over a wide range.


Drift Tube.

The Drift Tube is made from High alumina with a multi layer internal resistive coating that has been fired at high temperature. It therefore has a smooth internal surface that provides clean laminar flow of the sample gas with low memory efffects. The voltage gradient on the drift tube can be changed from 0V/cm up to 60V/cm.



The Drift Tube Assembly.

The picture opposite shows the drift tube and the differential pumping cones fitted to its support flange. The Ion source plugs into the back of this flange, and is easily accessed by the user. This unit plugs into the Drift Tube Housing that contains the differential pumping port, and a port that connects to the analyser housing.



Quadrupole Mass Spectrometer.
ASI have been designing and building quadrupole mass spectrometers for 40 years. The quadrupole analyser was designed specificately to optimise sensitivity and performance for the PTR-MS system.
An optional triple mass filter is available to provide a high sensitivity over the entire mass range, with a choice of mass ranges up to 500amu. A Special off axis electron multiplier has been selected for its high gain performance even at high operating pressures. It can be used for continuous current monitoring or in a pulse counting mode when the highest detection capability is required.
Control of the Mass Spectrometer is direct from a PC Computer and is supplied with comprehensive software for data storage and display.

Easy maintenance.

The PTR-MS system has been designed on a modular basis with easy access for service and maintenance of key components to keep 'Down Time' to a minimum.


PTR-MS Engine.

In addition to manufacturing complete PTR-MS Systems ASI are also prepared to supply the PTR Engine assembly to companies or research organisations that wish to build their own PTR-MS systems.


The complete PTR-MS Engine is briefly made up of the following components:-

1. Plug-in Discharge Ion Source.

2. Drift tube assembly

3. Drift Tube Housing

4  Differential Pumping assembly

5. Quadrupole analyser & Housing.

6. Quadrupole Electronic Unit (Not Shown)

7. Ion Source and Drift tube Electronic Unit. (Not Shown).

8. All connecting Cables.

9. Operating Software.


Contact ASI for further details



R & D applications for the PTR-MS System include:-

Food aroma/flavour measurement, 
Fermentation monitoring, 
Environmental monitoring & forensics, 
Arson investigations, 
Defense/security applications (explosives & their precursors or ingredients, chemical threat agents), 
Clinical applications (breath analysis, drug metabolism & development, 
Clinical microbiology), 
Biotech fermentation monitoring,
Industrial hygiene, 

For sales and further information on the PTR-MS System or Components Contact :-  



Contact Information

+44 (0)1805 625 205
Postal address
  Anglo Scientific Instruments,
  3, Devon Units, Hatchmoor Industrial Estate,
            Torrington, Devon. EX38 7HP. UK.
Electronic mail

All enquires: