Winner of the ACHR News Dealer Design Awards for excellence in product design! CFM without a calculator? The Kestrel® 4100 Pocket Air Flow Tracker makes it possible. For immediate and accurate air flow readings, simply enter the duct shape and dimensions, hold the 4100 in the air flow and the volume air flow readings are displayed... no calculator required! The Kestrel 4100 also measures temperature, relative humidity and dewpoint, either ambient or in any accessible airflow. This versatile instrument features a powerful data logger that records 2000 sets of measurements at userselectable time intervals (over 2 years of data can be recorded). You may review the logged data with the 4100’s on-screen graphing capabilities, or upload the data to a PC for in-depth review. The Kestrel 4100 is an affordable tool that is easy to carry and use and is perfect for facilities managers, HVAC equipment sales people, field installers and technicians. Measures * Current, average, and maximum air velocity * Volume air flow in cfm, L/s, m³/s, m³/m, m³/h * Air Velocity in ft/m, mph, m/s, km/h, kts, Beaufort * Temperature in °F or °C * Relative humidity in % * Heat stress index * Dewpoint Features * Waterproof and floats * Backlit display for low light conditions * Multi-Function 3-line display * Humidity sensor can be recalibrated in the field with our Relative Humidity Calibration Kit. * Automatic and manual data storage * Customizable data storage - 2000 data points * Data charting * Data upload (with optional interface) * Minimum, maximum, and average values * Five languages (English, French, Spanish, German, and Italian) * User-replaceable impeller * Flip-top impeller cover * US Patent Nos. 5,783,753 and 5,939,645 and 6,257,074 * All instruments and accessories are completely assembled in the USA * 2-year warranty Includes * Soft carry pouch * Wrist and neck lanyards * Batteries - 2 AAA * Kestrel Certificate of Conformity

FAQs about Kestrel and HVAC

How does the Kestrel CFM function work?

To measure volume airflow (CFM), simply select the duct shape that you will be measuring - either circular or rectangular - then enter the duct size, and hold the Kestrel into the air flow. Readings are automatically calculated and displayed on the screen in either cfm, m3/h, m3/m, m3/s or L/s. The Kestrel also features an averaging function that allows users to measure the air flow for a duct where the flow is variable. The user simply selects the averaging mode and traces the duct. It also has a hold feature if you need to take a measurement inside a duct that you can't se - just "hold" the value and it will be frozen on the screen until you can look at it. The Kestrel has an easy-to-read screen with step-by-step instructions on it to, making it extremely simple to use.

How can I be sure that the Kestrel's readings are accurate?

Every single Kestrel manufactured at NK is calibrated for every single value, either directly against NIST traceable standards or against an intermediary standard that is calibrated daily. Every unit is shipped with a FREE Certificate of Conformity that states what calibrations were performed, and the certified performance specifications. For an additional charge, NK can provide a NIST-traceable Certificate of Calibration that specifies exactly which values were measured in each multi-point calibration, and details the calibrated standard used for testing. Kestrel's 30-day satisfaction guarantee covers accuracy concerns as well.

How does the Kestrel log data, and can it upload the data to a computer?

The Kestrel 4100 and 4200 feature a 2,000 data point log. The user can set the Kestrel to store data automatically at a predetermined interval (anywhere from every 2 seconds to once every 12 hours), and/or data can be stored manually with a single button press. Each data point is stored with the date and time, and can be viewed as in chart form. The minimum, maximum and average values are stored for each reading as well. Data can be uploaded to a PC using the available Kestrel Interface (available as USB or serial).

What's so great about the Kestrel impeller?

The Kestrel impeller measures 1 inch across, and turns on a Swiss precision pivot mounted on sapphire bearings. Its large size ensures accurate readings even if pointed off-angle from the wind, and its very low start-up speed allows measurement of the lightest puffs of wind. If damaged, a new calibrated impeller can be purchased for $19 and popped in without tools, restoring like-new performance.

What's that curly looking thing?

That's the patented Kestrel temperature sensor. Unlike most watches and other products with temperature measurement, the Kestrel sensor is outside the case to ensure it measures the air, not your hand or pocket. The "curls" serve to further isolate the temperature sensor from the effects of the case temperature.

How does the Kestrel measure humidity so accurately?

The Kestrel features a patented dual temperature sensor configuration for rapid response and accurate measurement. Every Kestrel is calibrated against NIST-traceable standards, and can be recalibrated in the field with the Kestrel RH kit.

Do you really mean MADE in the USA?

Yes. The entire Kestrel line is designed and built in the USA. Some electronic components have to be sourced overseas these days, but we buy American wherever we can.