Hankinnan kuvaus
Institute for Atmospheric and Earth System Research of the University of Helsinki invites tenders for a high precision mass spectrometer with chemical ionization inlet. The analyser must be capable of measuring atmospheric trace gas concentrations at sub-ppt level. The analyser will be deployed in both laboratory and field measurements in various conditions.
The instrument should meet the following requirements:
(a) resolving power > 4 000;
(b) chemical ionization (CI) inlet which allows
1) use of multiple (at least two) reagent ions, including NO3-
2) measurements without ionization, in order to measure naturally charged ions;
3) fast (< 1 min) and automated switching between the different modes of operation mentioned above;
4) soft ionization and ion transmission, for measurements of ion clusters;
(c) detection limit of the device below 10^5 molecules/cm^3 for gas-phase sulphuric acid and low volatile organic compounds;
(d) can be used both in laboratory chamber measurements and ambient monitoring in field conditions;
(e) the instrument must be easily transportable and its overall weight should be < 175 kg;
(f) manufacturer must provide comprehensive analysis and data acquisition software;
(g) bipolar voltage supply to be able to measure in both positive and negative polarity;
(h) able to sample from atmospheric pressure.