DQRID : D980518.1
Start DateStart TimeEnd DateEnd Time Data Quality Metric
11/04/1997203011/05/19972230Suspect
more
Subject:
SGP/TWR/C1 - West RH Probe Replacement
DataStreams:sgp1440twr25mC1.a0, sgp30twr25mC1.a1, sgp1twr60mC1.a0, sgp1440twr60mC1.a0,
sgp30twr60mC1.a1, sgp1twr25mC1.a0
Description:
On 4-5 November 1997, the Qualimetrics RH probes were removed from the west
elevator 25 and 60 meter levels and replaced with Vaisala probes.  The
Vaisala probes had to be inserted upside down in the Qualimetrics
aspirators to make them fit.  Data during the period above is incorrect.
The west temperature probes appeared to need recalibration, so that was
done on 5 November.  Little improvement in the comparison of west and
southeast carriage temperatures can be detected in the data after 5
November.  RH comparisons show that the west and southeast side Vaisala
probes agree within 1% normally, with only a very occasional 3% to 4%
difference (when RH is greater than 90%).  West side temperatures are normally
greater in the daytime especially, an indication that the aspiration rate in
the west side aspirators is marginal, as I reported when they were installed 5
years ago.  The west side metal aspirators also have more thermal mass than the
plastic southeast aspirators; the combination of this with the lower aspiration
rate causes the west side temperatures to not drop as rapidly as those
measured on the southeast side when the temperature is decreasing.  The west
side temperatures are often 0.2 to 0.6 degrees higher than the southeast
side during the midday.  Obviously, when the temperature differences are large,
the RH tends to be slightly smaller on the west side.

The vapor pressure differences between the west and southeast sides are very
small, 0.03 kPa or less, usually much less, a result that should make the
WVIOP community happy.
Suggestions: 
Measurements:sgp1twr25mC1.a0:
  • vap_pres
  • rh
more
sgp30twr25mC1.a1:
  • rh
  • vap_pres
  • sd_vap_pres
  • sd_rh
more
sgp1twr60mC1.a0:
  • vap_pres
  • rh
more
sgp1440twr60mC1.a0:
  • min_rh
  • min_vap_pres
  • max_rh
  • max_vap_pres
more
sgp1440twr25mC1.a0:
  • min_vap_pres
  • min_rh
  • max_vap_pres
  • max_rh
more
sgp30twr60mC1.a1:
  • rh
  • sd_vap_pres
  • vap_pres
  • sd_rh
more

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