ECAC - Forum

Hello everyone,

we get sometimes 0x64 status codes from our Integrating Nephelometer TSI 3563.
Converted to "binary", 0x64 = 0000 0000 0110 0100 (using the number format as in the Table on page 6-23 of the TSI 3563 manual).
According to the manual, this would mean 'Pressure out of range', 'Temperature out of range', and 'Chopper fault'.
However, we don't see anything special about temperature and pressure, but very low RH (<= 1.0 %); and (casually?) rather low Sc values (<20 /Mm @ 450 nm) and sometimes dramatically different from what we measure before and after getting the 0x64 status flag.
Questions:
1- any hint regarding TSI 3563 status flags?
2- any suggestion on how to decrease the 'Chopper fault' frequency of occurrence?
2- any idea on how to flag data with status flag 0x64?

Thx and cheers,

jp

Hi JP,

this question would need to be answered by the TROPOS colleagues, so I can only contribute to the discussion in my role as fellow PI for aerosol instruments at ACTRIS stations.

I haven't seen the temperature and pressure out of range flags often, but I do see "RH fault" flag very often at Troll. In very dry air, the RH sensor in the 3563 can in fact indicate 0, which causes this error since the firmware takes such a reading as unphysical. I ignore that error for the RH sensor.

In my automatic QC, any data line indicating the "chopper fault" is marked as invalid and disregarded. If chopper and backscatter shutter aren't completely aligned and synchronised, either one of them would come into the light path during the wrong measurement period, and cause the jumps in the signal you describe. The firmware is very good in detecting this condition, the flag should be taken seriously. It usually means that the chopper and / or backscatter shutter motors have reached the end of their life and need to be replaced.

Regards,
Markus