Quantifying Uncontrolled Landfill Gas Emissions from Two Florida ...

calibration procedure differs from the procedure used to perform the annual calibration of the
instruments.
Additionally, a couple of reasonableness checks are performed in the field on the measured wind
direction data. While data collection is occurring, the Field Team Leader compares wind
direction measured with the heads to the forecasted wind direction for that particular day.
The project team experienced some difficulties with collection of wind data on February 21 at
Site #1. Due to problems with the data collection software, wind data were not collected on this
day. However, this problem was corrected, and wind data were collected for the duration of the
project. There was no indication that the problem experienced in collecting the wind data was
caused by a malfunction of the instrumentation.
5.2.5 DQI Check for Precision and Accuracy of Theodolite Measurements
Calibration checks are not performed before each field campaign; however, the calibration date
of the instrument is verified by referencing the calibration sticker. If the date indicates the
instrument is in need of calibration, it should be returned to the manufacturer before use in the
field. Before field deployment, ensure the battery packs are charged for this equipment. The
following additional checks were made on April 19, 2006. The calibration of distance
measurement was done at the ARCADIS facility using a tape measure. The actual distance was
19.6 meters. The distances measured with the theodolite were 19.56 and 19.55 meters. The
results indicate accuracy and precision fall well within the DQI goals. The calibration of angle
measurement was also performed. The actual angle was 360°. The angles measured with the
theodolite were 360°28’47” and 359°39’24”. The results indicate accuracy and precision fall
well within the DQI goals, and completeness was 100 percent.
Additionally, there are several internal checks in the theodolite software that prevent data
collection from occurring if the instrument is not properly aligned on the object being measured,
or if the instrument has not been balanced correctly. When this occurs, it is necessary to reinitialize
the instrument to collect data.
5.2.6 DQI Check for Lumex Mercury Analyzer
The Lumex Mercury Analyzer DQIs of accuracy and precision are checked with a test cell,
containing gas from the calibration standard. The cell is built into the instrument, and is accessed
by setting the instrument to the “test” mode, and collecting measurements. If the measured value
of the mercury vapor concentration in the test cell is within ±25 percent from that of the
tabulated value and the standard deviation of the measurements is within ±25 percent, the
accuracy and precision of the instrument are deemed acceptable.
The Lumex mercury analyzer was zeroed using the internal carbon filter sample conditioner.
Yearly calibrations are performed on this analyzer by factory personnel at Ohio Lumex. The
precision criteria of ±25 percent established in the QAPP was met for samples collected at Site
#1 (4.0% RSD), but not for samples collected at Site #2 (35.6% RSD).
5-6