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[MariCruz Minguillón <mariacruz.minguillon AT idaea.csic.es>]

Hi ACSM-users

I hope your are doing well. We had a problem with our ACSM, and I would like to ask you in case you have an explanation/solution.

We performed an IEcal and sulfate RIE cal and we got a change in HB reading (although the set HB was NOT changed), with a consequent AB drop. Moreover, the vap T also changed, without changing the set V.

I am attaching the diagnostics plots from 24 to 27th June so that you can see:

- 25th June, I tuned SEM and HB to get AB signal at 10-7.

- 26th June: IEcal and sulfate cal

- 27th June: keeps sampling with still low AB

The IEcal constant was lower than usual (about 2.4, while the last one was about 5.2), but the AB during calibration was about 0.5e-7, so the ratio (IEcal constant/AB) is very similar, so it makes sense. But, still I think it is not good to do the IE cal with such a low AB.

What can be the reason for this HB change? How to avoid it?

Afterwards, I did the following:

- We stopped scanning

- We turned off vap and ionizer settings

- We stopped the prisma, close the DAQ

- We disconnect the power from prisma and connect again

- Everything on again with the same settings it was before and during IEcal

- Check AB signal with the mz cal mode scan: 0.95e-7

So now I get the same AB signal as before without changing any settings. I started scanning again.

And now the vapT signal is not stable, it decreases from 600C to about 580C, and these fluctuations seem to track those from AB signal. Is this an electronics problem? or something else?

Thank you in advance for your help. Best regards

MariCruz

MariCruz Minguillón
Institute of Environmental Assessment and Water Research (IDAEA)
Consejo Superior de Investigaciones Científicas (CSIC)

Jordi Girona 18-26
08034 Barcelona, Spain
Tel. +34 934006100  ext. 1519
mariacruz.minguillon AT idaea.csic.es

Attachment: ACSM140-110_HBchange_ABdrop_IEcal_20140626.odp
Description: application/vnd.oasis.opendocument.presentation