New for 2007, the Kestrel 4200 has made HVAC technicians jobs even easier with automatic humidity ratio readings. Of particular interest to dehumidification professionals, the Kestrel 4200 measures relative humidity and calculates dewpoint, wet bulb temperature and heat stress index as well as the humidity ratio - and the patented dual chamber humidity sensor assures fast and accurate readings in any environment. Like the 4100, the Kestrel 4200 has taken the calculations and guess-work out of Air Flow measurements with automatic air flow readings. Plus it measures every other environmental parameter and stores over two years worth of information in its built-in data logger. With on-screen customization, the 4200 can truly be personalized for every technician. Easy set-up screens allow unit to display only relevant readings, and hide screens not relative to the job. Measures * Current, average, and maximum air velocity in ft/m, mph, m/s, km/h, kts, Beaufort * Volume air flow in cfm, L/s, m³/s, m³/m, m³/h * Temperature in °F or °C * Relative humidity in % * Humidity ratio * Heat stress index * Dewpoint * Barometric pressure * Wet bulb temperature * Altitude * Wind chill Features * Waterproof and floats * Backlight for low light conditions * Data Logger (automatic and manual) * Customizable data storage - 1600 data points * Minimum, Maximum and Average values * Multi-Function 3-line display * Data charting * Humidity sensor can be recalibrated in the field with our Relative Humidity Calibration Kit. * User-replaceable impeller * Flip-top impeller cover * Upload to a computer (with optional interface) * Five languages (English, French, Spanish, German, and Italian) * US Patent Nos. 5,783,753 and 5,939,645 and 6,257,074 * 2-year warranty * Assembled in the USA 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.