DQRID : D950501.2
Start DateStart TimeEnd DateEnd Time Data Quality Metric
04/30/1995163004/30/19951700Incorrect
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Subject:
SGP/MWR/C1 - IR thermometer calibration check
DataStreams:sgpmwrlosC1.b1, sgpmwrlosC1.a1
Description:
Mentor used an Everest model 1000 ambient temperature target 
(emis.=0.98) to check the calibration of the Heiman IR pyrometer
(IR thermometer).  Data collected during this period will be
anomalous due to the modifications of the instrument settings
required to facilitate the calibration.

The emissivity of the instrument was changed to match the target;
units were changed to deg C (from K) to match the target LCD units;
integration time on the instrument was changed to 3 seconds (from 1
second).

Centered the target on the instrument lens and allowed it to rest
on the lens barrel so that it filled the field of view of the
instrument. Both the instrument LCD and target LCD indicated 16.7
deg C.

Noted that although the lens appeared clean, there was some liquid
water around the edge which formed a meniscus with the inside of
the lens barrel. Wiped this away with a clean, lint-free cotton
cloth.

Replaced the target on the lens barrel; both instrument and target
then indicated 17.1 deg C.

Reset the instrument emissivity (=1.0), the units (kelvins) and
the integration time (=1 sec).

The IRT was deployed in December 1993.  Its calibration appears to
have been stable since deployment.  Liquid water around the edge of
the lens appears to be out of the field of view and does not appear
to affect the data.
Suggestions: 
Measurements:sgpmwrlosC1.a1:
  • sky_ir_temp
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sgpmwrlosC1.b1:
  • sky_ir_temp
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