Blog from September, 2012

September 25, 2012

Afternoon

Chris and Lisa

Replaced barometer with another barometer.  Do not know serial number on new unit.  It is coming in but not parsed the same.

Removed sonic at 8m and 30m.

From my reading of the logbook, the licors were at these heights, starting at the given dates:

level

Nov 18, 2009

Dec 2, 2009

Feb 2, 2010

Mar 29, 2011

Apr 12, 2011

Oct 14, 2011

Dec 15, 2011

Jun 26, 2012

Aug 15, 2012

2

0813

 

1163

removed all,
calibration

1166

1166

1166

removed all,
fire danger

0813

7

1166

1166

1166

 

 

0813

 

 

 

16

1167

1167

1167

 

1163
failed Oct 2, 2011

1167
failed Nov 6, 2011

0813

 

1164
failed Aug 23, 2012

30

1163

1163

 

 

 

 

 

 

 

43

1164

1164

1164

 

1164

1164

1164

 

1166

Failures:

Summer 2009: SN 0813, 1166 fixed at Licor after lightning damage prior to being deployed at Manitou.

Oct 2, 2011: 16m, SN1163, https://wiki.ucar.edu/x/cKmrB
Nov 6, 2011: 16m, SN1167, https://wiki.ucar.edu/x/jofpB
Aug 23, 2012: 16m, SN1164, https://wiki.ucar.edu/x/boHCBg

According to https://wiki.ucar.edu/x/HwClBg, the 16m licor is SN1164.

http://www.eol.ucar.edu/isf/projects/BEACHON_SRM/isfs/qcdata/plots/2012/08/23/licor_20120823.png

On Aug 23 18:48:30, the diag initially dropped from a good value of 249 to 118-121.

2012 08 23 18:48:30.5894  0.1001      49 249\t0.07072\t12.6021\t0.05373\t415.742\t19.45\t76.2\t\n
2012 08 23 18:48:30.6894     0.1      49 249\t0.07068\t12.6090\t0.05378\t416.812\t19.45\t76.2\t\n
2012 08 23 18:48:30.7894     0.1      49 121\t0.07176\t12.6058\t0.00112\t418.920\t19.45\t76.2\t\n
2012 08 23 18:48:30.8893 0.09994      49 119\t0.06758\t12.5810\t0.00463\t435.376\t19.45\t76.2\t\n
2012 08 23 18:48:30.9893 0.09998      48 118\t0.06661\t12.4256\t0.01945\t-6.373\t19.43\t76.2\t\n
2012 08 23 18:48:31.0896  0.1003      48 118\t0.06405\t11.7233\t0.03659\t56.809\t19.45\t76.2\t\n
2012 08 23 18:48:31.1894 0.09977      49 118\t0.06470\t11.6094\t0.04970\t170.629\t19.45\t76.2\t\n
2012 08 23 18:48:31.2893 0.09994      49 118\t0.06822\t11.0511\t0.06201\t287.164\t19.43\t76.2\t\n

After the number of bytes (49 or 48) is the licor data record. The data fields (diag,co2raw,co2,h2oraw,h2o,Tcell,Pcell) are separated by tabs (\t)

A diag of decimal 118 is binary 01110110,  where bits 0,3 and 7 are 0.

bits 0-3 are the AGC, automatic gain control.  The critical diag bits are 4-7.

See: ftp://ftp.licor.com/perm/env/LI-7500/Manual/LI-7500Manual_V4.pdf, page 3-36.

Bit 4 is Sync:

Sync Flag - If not OK, indicates that the LI-7500 embedded software and the digital signal
processor (DSP) receiving the signal from the chopper motor in the sensor head are out of
sync. Check cabling.

Bit 5 is the PLL:

PLL - Phase Lock Loop offset, indicates the status of the chopper motor. If not OK, there
may be a problem with the chopper motor in the sensor head.

Bit 6 is the detector:

Detector - If not OK, indicates the detector cooler is not maintaining the proper temperature:
this will happen at temperatures above 50 °C. Note that this does not always indicate a
serious problem; the cooler may simply have not yet reached the target temperature during
instrument startup, or it may be out of range due to external environmental conditions.
Readings may still be OK. Check cables and wiring.

Bit 7 is the chopper:

Chopper - If not OK, indicates the chopper temperature controller is out of range, hot or cold.
As with the Detector indicator above, this may or may not indicate a serious problem. The
chopper should be able to temperature control when ambient is between +50 and -25 °C.

Since Aug 23, the diagnostic value has been all over the map, with bits 5,6,7 changing over the day.
Here's a snippet of data from Aug 30. Diag=159, binary 10011111, bits 5 and 6 are 0 (not OK), bits 4 and 7 are OK.

159\t0.84090\tOverflow\t0.85015\tOverflow\t30.04\t76.3\t\n
159\t0.14794\tOverflow\t-0.15488\tOverflow\t30.04\t76.3\t\n
159\t0.74279\t1034826496\t0.88954\tOverflow\t30.06\t76.3\t\n

I think Tcell and Pcell have always looked OK.