When to Calibrate Your Kestrel

Every Kestrel Meter and Data Logger is factory calibrated, includes a Certificate of Conformity, and is built for long-term accuracy. However, environmental exposure and application use can affect calibration needs over time.

The following recommendation applies to these Kestrel Models: DROPs, Basic Series Weather Meters, Advanced Series Weather Meters, and Heat Stress Environmental Meters.

General Recommendation:

Harsh Conditions (Extreme heat, high humidity, or rugged use): Calibrate annually
Normal Use: Calibrate every 2 to 4 years
Not Sure? When in doubt, annual calibration ensures continued reliability.

Use the Calibration Chart below to help determine the best schedule for your specific use case.

Calibration Interval Recommendations by Application:

Calibration Interval Recommendations by Application
Application	Calibration Interval
Heat Stress Monitoring (Kestrel 3000 & 5400) — Occupational Safety Use	NIST-Traceable Calibration required: Every year Without NIST-Traceable requirement: Every 2–4 years Humidity Conditions High Humidity (>85–90%): Every year Mild to Low Humidity: Every 2–4 years
Athletic Events & Training	High Humidity (>85–90%): Every year Mild to Low Humidity: Every 2 years
Research Use	NIST Calibration recommended annually
Quality System / Company Standards	If your company standards do not require yearly calibration, we recommend every 2 years

Calibration Service Options:

Factory Calibration with Firmware Update

Calibration of all sensors relevant to your model
Functional testing, cleaning, and battery/impeller replacement
Firmware update for Kestrel 5000 Meters
Includes updated Certificate of Conformity and Calibration Report

Start a Factory Calibration Order

NIST-Traceable Calibration

NIST-traceable calibration of all selected sensors relevant to your model
Includes full NIST Calibration Report and Certificate
Report includes "as found" and "as left" values, observed test data, and deviation from standard
If needed, adjustments or replacements are performed to meet spec

Start a NIST-Traceable Calibration Order

Learn More:

Below are the typical drifts for each of the sensors found in Kestrel products as part of the consideration for calibration.

Wind Speed - Impeller will drift depending on usage. Drift will be < 1% at 100 hours of use with 16 mph winds.
Temperature - The thermistor is designed to be stable and should not drift, requiring infrequent recalibration over the life of the unit. However, exposure to undesirable environments or operator mishandling may affect its performance and necessitate calibration.
Pressure - The pressure should not drift and should not need to be recalibrated for the life of the unit. However, exposure to undesirable environments or operator mishandling may affect its performance and necessitate calibration.
Humidity - The humidity will drift independent of usage. Maximum drift of this sensor will be +/- 0.25% per year. WARNING: While not a complete list, vapors known to cause harm are those from cleaning solvents, HCl, H2SO4, HNO3, NH3, and ozone in high concentrations in combination with long exposure times, and may permanently damage the sensors and are not covered under warranty.
Black Globe - The black globe should not drift and should not need to be recalibrated for the life of the unit. However, scratches/damage on the black globe coating, exposure to undesirable environments, or operator mishandling may affect its performance and necessitate calibration.
Compass - The compass can be field self-calibrated to correct any known errors.