Interactive comment on “ Evaluation of the new capture vaporizer for Aerosol Mass Spectrometers ( AMS ) through laboratory studies of inorganic species ” by Weiwei

In their manuscript “Evaluation of the new capture vaporizer for Aerosol Mass Spectrometers (AMS) through laboratory studies of inorganic species”, Weiwei Hu and coauthors present results from extensive characterization measurements with the new capture vaporizer for the Aerosol Mass Spectrometers. The capture vaporizer (CV) is designed to reduce losses by particles bouncing off the AMS vaporizer. This is achieved by its geometry which helps directing bounced particles into a cavity where they have several additional chances to interact with the hot vaporizer surface. In their manuscript the authors investigate the impact of this vaporizer on thermal decomposition of inorganic aerosol components and associated changes in fragmentation patters, on collection efficiency for various inorganic aerosol types, and on the size distribu-


Interactive comment
Printer-friendly version Discussion paper explanation of the processes taking place during the vaporization and ionization steps of the AMS/ACSM and the influence of the vaporizer' type.The text is well supported by a large number of figures.This work is appropriate for AMT.However, the authors may consider the following comments before publication.

Specific comments:
-As mentioned in the introduction of the manuscript, Xu et al. ( 2016) already described the capture vaporizer (even if this early paper was focused on PM2.5 lens).This article also included a comparison with the SV based on similar inorganic species as in the present work (NaNO3, NH4NO3 and (NH4)2SO4) as well as investigated influences of vaporizer temperature, changes on fragmentation pattern including recommended modifications of the fragmentation table and particle sizing (PTOF-mode).In some aspects, the manuscript presents similar results as Xu et al. (2016).Therefore, the authors have to strongly emphasize their motivations, and to clearly justify what is new compared to this earlier work.A more systematic discussion should be made.For example, recommended modifications of the fragmentation table (as presented on Table 2) appears to be different from the ones presented in Xu et al. ( 2016), which is not discussed at all.Finally, it is unfortunate that the authors did not investigate organics or inorganic-organic mixtures for example.
-Section 3.1: I would suggest to reorganize this section since the authors first state that measurements were made at 500-550 • C (and not at standard 600 • C) but provide an explanation for this choice only later on (section 3.1.3).Therefore, it would be better to discuss the influence of the vaporizer temperature before the fragmentation patterns at a specific vaporizer temperature.
-Moreover, is there any reason why the authors decided to work at similar temperature?I think it would be more representative to compare the CV at 500-550 • C with the SV at 600 • C since both temperatures represent the optimal ones of the corresponding vaporizer.In this way, a clear parallel can be drawn between classical AMS/ACSM

Interactive comment
Printer-friendly version Discussion paper results and upcoming CV measurements.

Minor comments:
-Line 176: Please provide a link or server location where William et al. ( 2010) can be found.
-Line 188: Are the CU 2014 results really needed?Although the authors provide a clear statement to explain the nature of the bias, the correction factor of 0.6 is not justified.
-Line 294 & Fig. 4b: Do the authors have an explanation for the trend of NO2/NO ratio when Tv(SV) > 550 • C? -Line 380: The authors speculate about change on IENO3 on the edge of the CV compare to center position.Would it be possible to directly determine the IENO3 at this position?-Line 407: Should be Fig.7c -Line 424: Can the authors precise the vaporizer temperature during these 4 days?Was the temperature of the vaporizer only adjusted before the nitrate calibration?-Line 456: I am not fully agreeing with the sentence "this is the first time that AMS CE has been reported as a function of Tv".It might be true for the SV but not for CV since Fig. 10 from Xu et al. (2016) shows the AMS/CPC mass loading vs. temperature for NH4NO3, (NH4)2SO4 and a-pinene SOA (Fig. 10).
-Section 3.2: In Fig. 10, the authors describe the decrease of the AMS signal when closing the particle beam by estimating the lifetime of the signal decay (tau).However, they refer to two different units in the text: decay time and tau.It would be easier to use only one nomenclature.
-Fig. 10 and 11: Units of the x-axis are missing.