Kestrel 3550FW - Sensor Drift and Calibration; Impeller Sensor Maintenance; Temperature and Humidity Sensor Calibration; Pressure Sensor Calibration

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SENSOR DRIFT & CALIBRATION
Impeller
The Kestrel impeller calibration drift is less
than 1% after 100 hours of use at 16 MPH
| 7 m/s. Drift increases with higher-speed
use. For most users, the impeller will provide
accurate wind speed/air ow readings for
years if not physically damaged. However,
if your application requires extremely high
precision or if you perform frequent high-
speed readings, we recommend you replace
your impeller at one-year intervals. Every
replacement impeller is supplied with a
certicate of conformity and restores your
Kestrel’s calibration upon installation.
Temperature Sensor
The Kestrel temperature sensor exhibits
virtually zero drift over time and generally
does not require recalibration for accurate
performance during the life of the product.
If your industry or application requires
calibration or verication, please contact NK
or a certied calibration lab for options and
pricing.
Humidity Sensor
The Kestrel humidity sensor calibration may
drift up to two percentage points up or
down over 24 months. For high-precision
applications, we recommend recalibration at
24-month intervals. If you require calibration,
please contact NK or a certied calibration
lab for options and pricing. The humidity
sensor may also be recalibrated in the eld
using a Kestrel Humidity Calibration Kit
(NK PN-0802). Instructions for running the
recalibration routine are provided with the
Humidity Calibration Kit and may also be
found at www.kestrelinstruments.com/
mwdownloads/download/link/id/37/
Pressure Sensor
The Kestrel pressure sensor drift may be up
to 1 mbar over 12 months. For high-precision
applications, we recommend recalibration at
12-month intervals. If you require calibration,
please contact NK or a certied calibration
lab for options and pricing. The pressure
sensor may also be recalibrated in the
eld with reference to a known-accurate
and calibrated pressure standard. We do
not recommend simply recalibrating to a
local weather station as this may not be
accurate for your location. Instructions for
recalibrating the pressure sensor may be
found at www.kestrelinstruments.com/
category-service-calibration/kestrel-
calibration.
SENSOR DRIFT & CALIBRATION