2-O&M_Startup_r1l Section 2Page 16
EBTRON, Inc • 1663 Hwy 701 S., Loris, SC 29569 • Toll Free: 800-2EBTRON (232-8766) • Fax: 843-756-1828 • EBTRON.com
2.3.2. Assess the Verification Technique
2.3.2.1. DUCT SYSTEMS AND FAN MEASUREMENT
Ducted field measurements with handheld instruments can yield accuracies of 5% to 10% when an adequate
straight run of duct is available. Applications having multiple airflow measuring devices in the same air path
can compare one airflow measurement device to the other as part of the verification method.
Set the system for 100% recirculation and compare the supply airflow measurement device to the
return airflow measurement device. Verify the measurement in the best location for the field
measurement device.
Set the system for 100% outdoor air and compare the supply airflow measurement device to the
outdoor airflow measurement device. Verify the measurement in the best location for the field
measurement device.
2.3.2.2. OUTDOOR AIR INTAKES
Direct field measurement of close-coupled outdoor air intakes can approach and exceed 25%. Indirect
measurement techniques to determine the outdoor airflow rate using the difference between the supply and
return airflow rates or the ratios of the return air, outdoor air and mixed air (or supply air) temperatures should
be avoided since uncertainties almost always exceed 25%.
2.3.3. Adjust or Verify?
If the airflow measuring device is within the measurement uncertainty of the verification technique, EBTRON
strongly recommends that no field adjustment correction is made. EBTRON airflow measurement devices are
factory calibrated to NIST traceable standards. Field adjustment is not required when installed in accordance
to published guidelines.
If field adjustment is required, a gain and/or offset adjustment can be made to the output of the device by
manual entry (Section 3) or by using the Flow Adjust Wizard (Section 4).
If a one-point adjustment is made, make a gain adjustment rather than an offset adjustment to match
the device to the third-party reading.
Do not make an area adjustment in lieu of a gain adjustment since area is used to verify proper setup
of the airflow measurement device.
2.4. FOR MORE INFORMATION …
Congratulations! Your EBTRON airflow measurement device is fully operational.
For toll-free factory support call 800-2EBTRON (232-8766), Monday through Thursday 8:00 AM to 4:30 PM
and Friday 8:00 AM to 2:00 PM eastern time or contact your local representative.
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